Sustainability in the Built Environment

#### **Chapter 1**

## Perspective Chapter: Prefabricated Single-Family House of Reinforced Concrete on Two Levels Prepared at the Foot of the Work and Built in a Short Time

*Guillermo Yorel Noriega Aquise*

#### **Abstract**

A technical design of a prefabricated single-family house of reinforced concrete on two levels is developed, to serve and assist populations in need of housing and can also be used for populations in post-emergency circumstances, due to telluric causes, landslides, floods, and others, since it is required to replace destroyed houses in a short time. It exposes a production process of precast reinforced concrete elements, to be produced in the same place of the work, with a minimum of equipment and tools that exist in a small city. It is intended to establish a low-cost construction system with precast reinforced concrete elements, which will become a technological alternative to the traditional confined masonry construction. It presents six types of two-level houses. Likewise, it exposes the building process, the costs, and assembly of the building with prefabricated elements. The basic criterion is to manufacture the elements that do not exceed the capacity of the size of the manufacturing, transport, and assembly equipment. A simple process for assembly is examined, the lowest cost is determined, in terms of direct costs, and an analysis per square meter of building will be established.

**Keywords:** prefabricated houses, house costs, prefabricated elements, construction system, prefabricated construction

#### **1. Introduction**

The department of Arequipa is located on the southwestern slope of the Andes of Peru, presenting a desert coastline influenced mainly by the atmospheric systems of the Coast that favor the presence of hill formations in this area. To the east, steep valleys are formed in the direction of the headwaters of the rivers, canyons, and volcanoes. The city of Arequipa, capital of the department, is located at 2326 masl. According to Warren Thornthwaite's climate classification, it presents a type of climate E(d) B<sup>0</sup> , arid, temperate, and with a deficiency of humidity in all seasons of the year, it registers maximum temperatures from 22–23°C and a minimum temperature of 11°C in summer and 7°C in winter, with a total of 70 mm of rain per year, February being the rainiest month with 28 mm [1]. However, weather stations near the mountain range record cooler temperatures [2].

Arequipa is the second largest city in Peru, it is located on the Chili River strip and in the shadow of the Misti volcano. In the second half of the twentieth century, the city underwent an accelerated urbanization process of horizontal growth, converting cultivated areas into peripheries occupied by human settlements. This expansion has lowered the population density, giving rise to areas that lack basic services [3].

Arequipa increased its urban area by 208 km<sup>2</sup> , in 1984 it had 67.8 km<sup>2</sup> and in 2020 it occupied 275.8 km<sup>2</sup> . The green areas were reduced, especially in the districts of the northern cone, this growth is surprising and presents an unknown, regarding the quality of life in the newly inhabited areas, it is unknown if they have water, sewage, and electricity services. The total population of the city of Arequipa is 1,009,132 inhabitants, with 301,570 homes [4].

In this scenario, there is a need to have family homes in the city since there is an insufficient amount in response to population growth. The need is critical and prevailing in certain geographical spaces where telluric and catastrophic events occurred that significantly affected family homes, which in most cases were destroyed and, when assisted in post-emergency situations, are unable to replace the demolished homes, as well It happens in cases like Ica [5] in the Colca, Ichupampa [6], among others.

The construction processes used in Arequipa for the construction and reconstruction of houses are by the Confined Masonry procedure. This procedure has very high costs and demands more time, which implies that the construction processes are long and costly. Under this approach, the need for housing is not met, so there will always be a need for housing or an unsatisfied demand.

Faced with this need, it seeks to establish an alternative for the construction of single-family homes with prefabricated concrete elements established at the foot of the work with tools and equipment that cities have, with techniques and procedures that are easy to assimilate and that can be available to a population. in need of building a house. With this the periods and construction costs are shortened, and this will allow for satisfying the need for housing.

The process of building a house with prefabricated elements is more efficient than the process of building with confined masonry. In this sense, we are going to present in detail the construction process of a single-family house with two levels of precast concrete elements, it is sought that the processes are simple and easy to assimilate. The design is simple, and the lowest costs and easy construction are sought. The complexity of design and building processes is not considered in the following presentation.

#### **2. Frame of reference**

#### **2.1 The traditional confined masonry building**

Confined masonry is a system that is traditionally used in almost all of Latin America. Confined masonry is defined as that which is entirely bordered by reinforced concrete elements (except for the foundation, which can be made of cyclopean concrete and in other cases reinforced concrete), emptied after the masonry wall has been built and with a distance between columns that does not exceed more

*Perspective Chapter: Prefabricated Single-Family House of Reinforced Concrete on Two… DOI: http://dx.doi.org/10.5772/intechopen.113351*

than 2 times the height of the floor. It is important to follow the indicated construction sequence so that the confines adhere to the masonry and form a set that acts in an integral manner [7].

Confined masonry is the construction technique used for the construction of a house and fired clay bricks, tie columns, screed beams, etc. are used. Confined masonry is the set or construction system formed by a brick wall, reinforced at the ends by tie columns and at the top by a concrete beam. The walls are vertical structures that separate a house from the outside or from the street. They avoid cold or heat and create different environment such as the living room, dining room, bedrooms, bathroom, and other spaces [8].

It is important that they are well built, and that they are perfectly vertical. Each brick must be settled or laid with the proper amount of mix. This mixture is called mortar, a combination of cement, coarse sand and water. A well-constructed wall is important because it can provide security and reduce finishing cost. There are two types of walls: load-bearing and non-bearing. The load-bearing wall receives the weight of the structure or is where the concrete joist rests and transmits it to the foundation. It is recognized because it is perpendicular to the joists [8].

The non-bearing wall, also known as "partition". It is the wall that does not receive any vertical weight, or that is not supported by the joist. It is always parallel to the joists, which are the concrete elements in the ceiling. It is normally suggested that load-bearing walls be wider than non-load-bearing ones, that first-story walls be wider than second-story walls, or that those on the first floor are of one type of brick and those on the second of another [8].

The government of Peru, through the National Training Service for the Construction Industry (SENCICO), develops technical training courses for masonry. It is a 447 hour face-to-face course that imparts training knowledge for a bricklayer. The Mason is the qualified operational worker who performs masonry work, such as the construction of walls, concrete floors, lining with mortar, ceramics, and porcelain; as well as the emptying of concrete elements; considering the technological knowledge related to the activities carried out, selecting with technical criteria the materials, instruments, tools and equipment necessary to carry out their work, observing the safety and quality conditions established in the plans; under the supervision of the master builder [9].

The construction processes are carried out within the framework of the national building regulations and the confined masonry construction process is considered in this regulation [10].

In Peru, knowledge of the confined masonry building process is widespread, there is technical and higher education training in confined masonry. Almost everyone uses this construction process and as a result, construction processes are achieved that require more time and cost. The need for housing persists.

In Latin America, it is one of the most widely used processes [11], and the housing requirements are similar almost throughout this geographic space.

#### **2.2 The building proposal with precast elements of reinforced concrete**

The National Association of the Precast Concrete Industry of Spain ANDECE defines a precast concrete product as a part manufactured in a fixed production plant, using concrete as the fundamental material. Said element is the result of an industrial process carried out under a defined production control system. Once manufactured

and all the controls satisfied, this piece can be stored until it is delivered to the site where, together with other pieces, they will make up the final construction project [12].

The precast concrete elements are produced in a place other than their placement and are then transported, hoisted, assembled, and assembled in their final place so that they make up the complete structure. In a construction industrialization process, it is known as prefabrication. Term that refers to the production (on the construction site or outside of it) of the component elements of a structure, which will later be transported, hoisted, and assembled in their final place; so that they make up the complete structure [13, 14].

In the prefabrication process, it incurs the improvement of the construction process, faster control and detection of problems is carried out and it is carried out by specialized personnel. About the prevention of occupational risks, the risks are reduced due to less exposure of workers and a much safer environment for the development of the activity [15].

The prefabrication process contributes to sustainability, it is about manufacturing prefabricated concrete elements to assemble in a housing assembly, the advantages of carrying out in full execution *"in situ"* is expressed in the reduction of lower energy consumption, less waste generation, less dust emission, less noise generation, and reduction of transportation of materials.

On expressly prefabricated structures, which are constituted totally or partially by independently emptied elements, which are later assembled to form the total structure. The design of the precast elements consists of defining their configuration based on resistance criteria, considering factors such as: place of manufacture of the pieces, their construction procedure, weight of the elements and available lifting equipment, place of storage, curing and transport, detailing the connections between pieces [16].

The design and execution of works that consider the precast elements must be carefully planned. Determine the geometry of each part, its final location in the structure, the pipes and inserts it must contain, the connections between elements, etc. They must be clearly defined before the start of the work. It is important to consider that the manufacture of parts in series increases the efficiency of the process and allows greater control of its quality. The possibility of reusing equipment and formwork is increased [16].

The productive activities in the construction industry have had two inevitable trends of modernization; concrete quality and duration of the process are relevant factors. These two factors must be evaluated in the case of precast concrete structures. In particular, the last one, duration is a relevant factor in the cost of work, so savings of not only days but also months in some cases that can be obtained with prefabricated structures. It is this reason that can widely justify the use of precast concrete structures [17].

In quality control, precast concrete structures can far outperform the construction of cast-in-place concrete structures. The elaborate details of placing reinforcing steel in areas of possible plastic hinges in precast concrete frames can be carefully supervised in the plants that produce the precast elements [17].

There is a factor of opposition, to the use of prefabricated structures, the fear of innovation stands out, due to ignorance of the new construction processes. As in the case of areas with moderate or high seismic activity, there is a fear that precast concrete structures may behave less favorably in the face of earthquakes, as in the case of cast-in-place concrete structures. This fear should not exist, because it is possible to *Perspective Chapter: Prefabricated Single-Family House of Reinforced Concrete on Two… DOI: http://dx.doi.org/10.5772/intechopen.113351*

build prefabricated concrete structures with a seismic behavior similar to that of structures cast in place [17].

In summary, using precast concrete structures requires less labor, which is supported by the analysis of the use of labor, which implies that, by building precast concrete structures, with less execution time, they could save significant amounts of money. This is a challenge that engineering must face as part of the important changes in today's economy [17].

Our position is to look for the simplest possible outlines that allow us to reduce costs and the processes are short, in such a way that the proposed knowledge is easily assimilated by the population and technical personnel. Our proposal does not consider complex and high-cost designs, our proposal states that the diffusion will be massive.

#### **3. Methodology**

The comparison process is still an essential technique to find answers to problems of natural and social knowledge. The differences that exist between comparison as a way of thinking and as a scientific procedure are important. The first compares simple operations; the second compares complex operations. The difference lies not in the complexity of the logical structure of the comparisons, it does not present significant contrasts in science and everyday life, but in the selection and definition of the objects and properties that are compared, as well as in the care and systematicity of the production procedures and analysis of the data from which the comparisons are made [18].

The comparative method consists of empirical generalization and hypothesis verification. Among the advantages offered by the comparative method are the understanding of unknown things from the known, the possibility of explaining and interpreting them, outlining new knowledge, highlighting the peculiarities of known phenomena, systematizing information, and distinguishing differences with similar phenomena or cases [19].

The comparative method is inherent to any scientific procedure, that is, it allows us to compare the results obtained after analyzing certain variables and observing the indicators. This supposes that whenever it is compared following scientific procedures. It will be possible to compare; in which aspects they are comparable and follow the analysis strategy to reach some conclusions. No type of unconscious comparison is understood, which is not premeditated, rather it is based on established objectives [20].

For the comparison process, on the one hand, there are single-family homes designed and built with precast elements of reinforced concrete, and on the other hand, there is a design and construction of confined masonry. To carry out a comparative analysis, the factors and analysis variables have been established in both cases in such a way that the indicators and response variables can be compared objectively.

The methodological design allows us to express the procedures to respond to the approaches and achieve the objective of the Study and thus respond coherently to the guiding principles, in the search for answers that respond to the existing need.

Architectural and structural designs and construction processes are analyzed according to the approaches and the specified and delimited premises. To define the costs, the budget, and the times required for the construction of basic single-family homes to define a technical proposal that allows serving populations in need of

housing in various areas of the cities and situations of post-emergency. The results analysis should achieve:


#### **4. Results**

#### **4.1 Design and development of basic housing**

Before the design of the houses, an exploratory and interpretation action was carried out on the type of houses that have been built in the last 20 years in the north of the city of Arequipa, the observation and a response it was obtained that the types of houses respond to an immediate need, that is to say, an inhabitant said that he wants as a home, an environment that houses him must have at least four walls and a roof, which must cover all the members of his family. This expression is to interpret the response of the geometry of the houses, and they are what are called constructions of the irregular box or cube type and are built with confined masonry. As their economy grows, they add irregular cubes until they form a large set of environments that allow them to develop their lives. When the economy of these families grows, they develop a more detailed and complex housing design.

The design of the houses is simple, based on the minimum necessary space, this is how the common areas that are used in the building are reproduced construction of houses and with the minimum possible space and in the same logic of the geometry of the house. With all this, the basic design criteria are established.

The design of the houses allows us to carry out a greater analysis with the use of the comparative method, with the purpose of making observations in greater detail of the proposed variables and indicators. Architectural and structural designs and construction processes are analyzed. To define the costs, and the budget that the construction of the houses demands.

The unit of study is the infrastructure of the domestic single-family home. According to the RNE, it is established that the plot of land where the house will be built is of Type 3, which gives a coverage of 160 m2 of surface. The designs made are smaller than the assigned area and both the first and second levels are built in this area.

To carry out an analysis and achieve a greater response from the comparative method, the dominant design principle is that the useful surface of the environments of the designs are equal, that is, the useful areas of a bedroom, are the same in both types of design (prefabricated and confined masonry), as well as in all the components of the house. The outstanding and visual difference is in the thickness of the walls, in the prefabricated house it is 0.12 m and in the houses with confined masonry it is 0.15 m, and structurally larger columns and beams are added, which responds to the structural analysis. The total area occupied by a prefabricated house is less than a house with confined masonry.

#### **4.2 Two-story prefabricated single-family home (VUF2)**

Six types of single-family housing of varied dimensions of length and width are considered, whose product expressed in the surface of a level is 38.67 m<sup>2</sup> , 54.10 m<sup>2</sup> ,

#### *Perspective Chapter: Prefabricated Single-Family House of Reinforced Concrete on Two… DOI: http://dx.doi.org/10.5772/intechopen.113351*

59.97 m<sup>2</sup> , 68.58 m<sup>2</sup> , 77.85 m<sup>2</sup> , and 89.72 m<sup>2</sup> and on this same area it is built. The second level resulting in twice this built-up area (**Table 1**).

The types of houses are shown in **Figures 1–6**.

#### **4.3 Basic single-family dwelling-confined masonry (VAC2)**

Six types of single-family basic housing built by confined masonry of various dimensions of length and width are considered, whose representative product in the constructed area on one level are 39.99 m<sup>2</sup> , 55.90 m<sup>2</sup> , 61.60 m<sup>2</sup> , 70.59 m<sup>2</sup> , 80.41 m<sup>2</sup> , 92.02 m<sup>2</sup> , and on this same area is built on the second level, as a result it is twice this built area.


**Table 1.**

*Areas and codes for two-story prefabricated single-family housing (VUF2).*

**Figure 1.** *Plan view VUF2-01 first level and second level.*

#### *Prefabricated Construction for Sustainability and Mass Customization*

**Figure 2.** *First level and second level plan view VUF2-02.*

**Figure 3.** *First level plan view and second level VUF2-03.*

The designs of houses with confined masonry are similar to the design of houses with prefabricated elements, the variation is in the width of the wall and the details that are followed in a building by confined masonry (**Table 2**).

Diagrams of plans for the construction of a house with confined masonry are presented, the design is a complex system that requires further analysis and for the *Perspective Chapter: Prefabricated Single-Family House of Reinforced Concrete on Two… DOI: http://dx.doi.org/10.5772/intechopen.113351*

**Figure 4.** *First level plan view and second level VUF2-04.*

**Figure 5.** *First level plan view and second level VUF2-05.*

construction, more time is required for its construction, as well as a greater amount of materials, and which gives a answer that the building processes by confined masonry have a higher cost than the buildings with prefabricated elements (**Figures 7–11**).

#### **4.4 Comparison of surfaces of environments of VUF2 and VAC2**

To carry out a correct application of the comparison methodology, the important factor is considered the principle of similarity–equivalence as well as the surface of the

#### *Prefabricated Construction for Sustainability and Mass Customization*

**Figure 6.** *First level plan view and second level VUF2-06.*


#### **Table 2.**

*Areas and codes of single-family housing confined masonry of two levels (VAC2).*

environments both of VUF2 and equal to VAC2. This implies that the areas of occupation and use of the environments of the dwellings are the same in the corresponding type of dwelling. The areas occupied by the passageways and stands are also the same.

On the other hand, the surface occupied by the walls are different, this is due to the fact that the wall occupied by prefabricated elements is less than the spaces occupied by the building by confined masonry and the difference must lie in the width of the wall of prefabricated houses is 0.12 m and that of confined masonry is 0.15 m (**Tables 3** and **4**).

Regarding the percentage ratio of the area occupied by rooms in relation to the total built surface, the areas occupied by rooms are greater in homes with precast concrete elements than those built with confined masonry. On the other hand, the surface occupied by masonry walls is greater than the percentage of the surface occupied by houses built with confined masonry (**Tables 5** and **6**).

*Perspective Chapter: Prefabricated Single-Family House of Reinforced Concrete on Two… DOI: http://dx.doi.org/10.5772/intechopen.113351*

**Figure 7.** *Plan of the foundation and lightening of a VAC.*

**Figure 8.** *View of column and continuous foundation in VAC confined masonry.*

#### **4.5 Building process of a house with prefabricated elements VUF2**

Usually, the manufacture of precast concrete elements is normally carried out in fixed production plants, which are equipped with the necessary machinery and specialized personnel that comply with the standards and projected design. In a production plant, prefabricated elements can be produced to make homes with complex designs and works of art a reality with specialized personnel. Of all this, there is a lot of experience.

Our proposal goes to the extreme of what exists, and it is intended to carry out a process to elaborate prefabricated elements of reinforced concrete at the foot of the

#### **Figure 9.**

*Column section and detail of the necessary iron in VAC confined masonry.*

**Figure 10.**

*Section of plates, footing, and detail of the necessary iron in VAC confined masonry.*

#### **Figure 11.**

*Lightening section of the first level in VAC confined masonry.*


#### **Table 3.**

*Detail of the rooms on two levels by surface area in square meters (VUF2).*

*Perspective Chapter: Prefabricated Single-Family House of Reinforced Concrete on Two… DOI: http://dx.doi.org/10.5772/intechopen.113351*


#### **Table 4.**

*Detail of the rooms on two levels by surface area in square meters (VAC2).*


#### **Table 5.**

*Detail of the rooms on two levels by occupancy percentage (VUF2).*


#### **Table 6.**

*Detail of the rooms on two levels by occupancy percentage. (VAC2).*

work with the equipment that exists in common cities. For which the equipment to be used must have the property of self-mobilizing to a place with minimum conditions and that they are in the place where the prefabricated houses are assembled.

Prefabricated concrete houses are structures that are built using precast concrete panels, the panels are made on the building site and then it is where they are assembled to form the structure of the house. The characteristics that must be fulfilled are:

• The prefabricated panels are made using molds and formwork, which can be of different sizes and shapes, and are framed in the project design. The panels make up the wall, ceiling, and floor. Steel reinforcement is installed between the panels as designed to provide strength and stability.


The machines and equipment to be used are:


Initially, the beams and foundation slab must be installed. On which the other pieces of prefabricated elements required for the construction of the prefabricated house will be installed.

To make the other prefabricated parts, the necessary molds must be available where the elements must be made to carry out mass production, considering the defined technical specifications. The molds are the fundamental part and respond directly to the results. Its design must respond to the specific requirements of the projects. However, efficiency increases when a mold or a reduced number of molds can be versatile and can produce a wide variety of precast concrete elements and allow the development of various types of works. Meeting the requirements in terms of dimensions, stability, and low deformation.

To make the various prefabricated elements of the six basic single-family homes, a 2.40 m 12.60 m mold has been designed with a variable thickness of 0.12–0.50 m, designed from iron plate, having to have several molds, which have devices that can shape smaller pieces and variable configuration, as well as shape the doors and windows, it must also allow placing the sanitary and electrical installations, before the pouring of the concrete.

The concrete used in manufactured homes can vary depending on the specific design, and structural requirements, and the following must be considered:

*Perspective Chapter: Prefabricated Single-Family House of Reinforced Concrete on Two… DOI: http://dx.doi.org/10.5772/intechopen.113351*


To carry out the elaboration of precast concrete elements, the following process must be carried out:


Once the necessary parts have been obtained, after obtaining the due and proven resistance, we proceed to carry out the assembly (**Figures 12–19**).

**Figure 12.** *Foundation beam installation.*

**Figure 13.** *Installation of foundation slab and walls.*

**Figure 14.** *Dividing and perimeter walls.*

**Figure 15.** *First level ceiling installation.*

#### **4.6 Structure of precast elements of reinforced concrete**

The structural system of precast concrete elements includes the following elements: foundation beams, and foundation slabs—floor, walls, and roof, under an approach of articulated structural panels with anchors that support the stress requests. *Perspective Chapter: Prefabricated Single-Family House of Reinforced Concrete on Two… DOI: http://dx.doi.org/10.5772/intechopen.113351*

**Figure 16.** *Dividing walls 2nd level.*

**Figure 17.** *Perimeter walls 2nd level.*

**Figure 18.** *2nd level ceiling installation.*

**Figure 19.** *VUF2 finished prefabricated.*

The elements must reach a sufficient resistance for handling and assembly. They must withstand the weather and the inclemency of the place.

Each element of the reinforced concrete panels that go on the floor, the walls, and partitions must have a minimum resistance of 210 kg/cm<sup>2</sup> with mesh every 0.20 m in both directions of iron with a diameter of 3/8″ in diameter and on the perimeter Next to the edge there are two equidistant irons with a diameter of 1/2″ in diameter, they are also installed as reinforcements in the corners and critical places. Lifting and transport devices are installed. It is possible to use various anchoring systems if it responds to the effort requests that the prefabricated parts require.

The elements of the roof are 0.20 cm thick and have a double 3/8″ mesh and on the perimeter, there are two parallel ½″ irons in each mesh, it is also placed in the critical links.

Two panels with exposed structures are shown, the others show a similar constitution (**Figures 20** and **21**).

Rectangular finite elements have been used whose formulation obeys a thin sheet behavior which is adequate for the representation of 12 cm thick walls, establishing a

**Figure 20.** *Structure of a front part of the VUF2.*

**Figure 21.** *Structure of a rear part of a VUF2.*

#### *Perspective Chapter: Prefabricated Single-Family House of Reinforced Concrete on Two… DOI: http://dx.doi.org/10.5772/intechopen.113351*

consistent mesh with the compatibility of deformations in the nodes and with the appropriate level of precision. For the interpretation of the results (**Figure 22**).

There are various types of anchoring devices and connections for use in manufactured homes that may vary depending on the specific design and requirements of the structure. Some common types of anchors are presented, which are connection devices between precast panels, which are:


It is important to note that the selection and design of the anchors depend on the configuration of the structure, the load forces, and the strength requirements, to guarantee a safe and reliable connection of the plates in the prefabricated houses.

A vertical anchoring system has been designed that can be used in critical places and can respond to greater demands, this model is still being tested and could be used, in our analysis it allows to give greater resistance to the designed structures of prefabricated houses of reinforced concrete. The use must respond to the structural calculation proposed by the structuralists. This unit can be additionally placed in the critical corners of the connection of the panels, which require greater demands, the internal mesh is ½″ iron placed equidistantly and parallel according to the senses. The connection of the

**Figure 22.** *Structural model of housing panels and front view structural model.*

**Figure 23.** *Prefabricated anchoring for panels of a VUF2.*

device with the panels is done with a bolt that responds to your structural requests and must necessarily be covered with elastomeric tape (**Figure 23**).

#### **4.7 Direct costs of VUF2 and VAC2**

The direct cost refers to all those expenses that are directly related to the construction of a work, it will be expressed in the amount of labor, materials, and equipment used in the execution of a work, which will be expressed in national currency and in US dollars at the exchange rate when the budget was prepared.

Six designs of houses with prefabricated elements have been carried out to explore the changes and variations that may exist in the process of building houses with prefabricated elements, in such a way that the comparative methodology allows us to know in greater detail the process of elaboration and construction of prefabricated houses.

For each type of housing designed, architectural and structural plans have been developed, from which the corresponding measurements have been made. These measurements were processed in the S10 cost and budget program.

The costs of prefabricated houses per square meter are shown, according to the type of VUF2 house. For each construction item, an analysis of unit costs was carried out, indicating the number of materials used and considering the equipment and machines necessary for its manufacture and assembly.

The cost of a two-story prefabricated house is in the range of US\$ 27,976 US dollars, which corresponds to a VUF2-01, and the VUF2-06 house, which has a cost of US\$ 64,218 US dollars. The lowest cost per square meter corresponds to housing VUF2-04, which is US\$ 304.18 US dollars, and the highest cost per square meter corresponds to VUF2-05, which is US\$ 391.25 US dollars (**Table 7**).

Six housing designs have also been made to be built with confined masonry, to explore the changes and variations that may exist and, at the same time, make a comparison with the houses built with prefabricated elements (**Table 8**).

*Perspective Chapter: Prefabricated Single-Family House of Reinforced Concrete on Two… DOI: http://dx.doi.org/10.5772/intechopen.113351*


#### **Table 7.**

*Direct cost of a VUF2 in US dollars.*


#### **Table 8.**

*Direct cost of a AC2 in US dollars.*

The cost of a house built by confined masonry is in a range of US\$ 38,670 US dollars, which corresponds to an AC2-01 and the cost of the house in AC2-06 is US\$ 97,712 US dollars. The lowest cost per square meter corresponds to housing AC2-04 which is US\$ 423.94 US dollars and the highest cost per square meter corresponds to AC2-05 is US\$ 537.42 US dollars.

A comparison has been made between the costs of a building with precast elements of reinforced concrete and a confined masonry design. The confined masonry process is a system that is traditionally used in Peru and Latin America.

Confined masonry is defined as that which is completely bordered by elements of reinforced concrete [8]. Although the designs represent a higher cost compared to prefabricated houses, it does not imply that the confined masonry process is limited, rather it requires a lot of experience to achieve greater efficiency and reduce labor costs to their maximum expression (**Figure 24**).

The design of the prefabricated houses has been modeled by anti-seismic structural calculations with a response of equal magnitude. Once this similarity has been achieved, the measurement analysis has then been developed and processed in the S10 cost and budget program, in Microsoft Project, and SPSS.

The cost trend of the confined masonry building process is higher than the cost trend of a manufactured home. Probably, the complexity of the design and the construction process of the confined masonry affects its higher cost, while in the building with precast elements, the simplicity of the design and the construction process guide its tendency to have the lowest cost (**Figure 25**).

The dimensions used for the building surface correspond to the observations made by the inhabitants who develop their homes, these chosen surface dimensions respond

#### *Prefabricated Construction for Sustainability and Mass Customization*

**Figure 24.** *Cost/area trend lines of VUF2 and AC2.*

**Figure 25.** *Cost trend/area lines of VUF2 and AC2.*

to the needs of the inhabitants. It can likely be understood that this chosen sizing represents a group of dwellings that are in the lower part of the polynomial, the higher the built-up area the prices per square meter would tend to rise, and if the prices per square meter are less than this chosen area. Costs per square meter would be higher than houses built with smaller surfaces.

*Perspective Chapter: Prefabricated Single-Family House of Reinforced Concrete on Two… DOI: http://dx.doi.org/10.5772/intechopen.113351*

#### **5. Conclusions**


### **Conflict of interest**

"The authors declare no conflict of interest."

#### **Author details**

Guillermo Yorel Noriega Aquise1,2

1 Catholic University of Santa María Arequipa, Peru

2 Magister Construction Management, Peru

\*Address all correspondence to: gnoriega@ucsm.edu.pe; gmonoriegae@gmail.com

© 2023 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

*Perspective Chapter: Prefabricated Single-Family House of Reinforced Concrete on Two… DOI: http://dx.doi.org/10.5772/intechopen.113351*

#### **References**

[1] Castro A et al. Climates of Peru: National climate classification map. In: Climates of Peru: National Climate Classification Map. Lima Peru: SENAHMI; 2021. pp. 70-70

[2] Noguera Yauri BF. Climate Model Prototype (Integrated Climate Model MEPDG AASHTO 2008) for the Design of Flexible Pavements in the City of Arequipa. (Thesis to obtain the title of Civil Engineering). Arequipa Peru: Catholic University Saint Pablo; 2020

[3] Harte J. Cities for Life Forum, Sustainable Transportation Pedestrianization of the Historic Center of Arequipa, Country Peru, Arequipa City. Lima, Peru: PICU International Urban Cooperation Program; 2017

[4] Arela Bobadilla R, Riesco Lind G, Chávez Contreras G. A Look at the Expansion of the City of Arequipa in the Last 40 Years. Arequipa, Peru: Studio Programmatic University Publication; 2021

[5] Successful Radio, Mayor of Ica: Nothing has been done for Pisco 10 years after the earthquake. Available from: https://exitosanoticias.pe/alcalde-icanada-se-ha-hecho-pisco-10-anos-del-te rremoto/.ed. [Accessed: August 15, 2017]

[6] Condori Z. Two Years after the Earthquake in Colca, Families from Ichupampa Continue to Live in Modules. Lima, Peru: Diario el Comercio; 2018

[7] San Bartolome A, Quiun D, Silva W. Design and Construction of Seismic Resistant Masonry Structures. Lima, Peru: Pontifical Catholic University of Peru Editorial Fund; 2014

[8] Institute of the Peruvian Chamber of Construction CAPECO. Confined

masonry. Master builds well Lima Peru. 05 15 2018

[9] Muñoz Mendoza GM, Saldarriaga Castillo RM. SENCICO Higher Technical School-Trujillo zonal headquarters. Thesis to opt for the Title of Architect, Descriptive report of the Architectural Project, Antenor Orrego Private University Faculty of Architecture, Urbanism and Arts Professional School of Architecture, Trujillo Peru. January 2021

[10] Ministry of Housing, Construction and Sanitation MVSC Peruvian Government - National Training Service for the Construction Industry, National Building Regulations DS No. 011-2006— Housing. Lima, Peru: The Peruvian; 2006

[11] Crisafulli FJ, Genatios C, Lafuente M. Social interest housing in Latin America a Guide To Earthquake-Resistant Construction Systems Geo POLIS Series Seismic Engineering. Caracas, Venezuela: CAF-Development Bank of Latin America; April 2020. ISBN: 978-980-422-057-9

[12] The National Association of the precast concrete industry in Spain [On-line]. Available from: https://www. andece.org/prefabricados-de-hormigon. html

[13] Maspons ET. Prefabrication. Havana, Cuba: ISPJAE; 1987

[14] Cordoví YS, Quintana INV. From current prefabrication technology to custom prefabrication. Ciencia en su PC. 2017;**1**:104-115

[15] Tenorio JA, Garcia Roll JL, Rios Tolmos J, Sorribes Gil M, Pinto M.

Industrialization of the Construction Process. Madrid, Spain: Spanish Association for Quality; 2013

[16] Harmsen TE. Design of Reinforced Concrete Structures. Lima, Peru: Editorial Fund Pontifical Catholic University of Peru; 2005

[17] Rodriguez ME. Modern precast construction systems. In: I Congress of Structures and Construction organized by the Peruvian Chapter ACI; Lima, Peru. 2002. p. 6

[18] Piovani J, Krawczyk N. Comparative studies: Some historical, epistemological and methodological notes. Educação & Realidade. In: Academic Memory. Vol. 42. Issue 3. National University of La Plata, Faculty of Humanities and Educational Sciences. 2017. pp. 821-840. Available from: http://www.memoria. fahce.unlp.edu.ar/art\_revistas/pr.8927/ pr.8927.pdf

[19] de Leon CGD, de la Garza EADL. Comparative Method. Monterrey, México: Autonomous University of Nuevo León (UANL); 2014

[20] Fuentes-Romero JJ, Rodríguez Fernández V. A bibliographic review of comparative studies. Its evolution and application to library science. Inter-American Journal of Library Science. 2009;**32**(2):411-433

#### **Chapter 2**

## Perspective Chapter: Achieving Sustainable Housing for Low and Middle-Income Earners

*Godwin Keres Okereke and Victor Arinzechukwu Okanya*

#### **Abstract**

The problems confronting cities and urban areas in many developing nations include urban sprawl, housing, massive disregard of urban planning and development regulations, poor urban environments and traffic congestion. Of all these challenges, housing issues poses one of the most serious challenges especially on low and middleincome earners. Issues of human well-being, having access and affordability of housing units to low and middle income earners are of grave interest not only to the people of the developing countries but also to the world at large given the significant impact that housing has on socio-economic development of man. Access to decent housing in cities and urban areas in developing countries continues to be a problem, especially for low and middle-income households. This paper highlighted the benefits of applying prefabricated systems, mass customization to the low-middle family homes; the challenges faced in integrating affordable, sustainable housing and strategies for solving sustainable affordable housing challenges among low and middle-income earners through literature review.

**Keywords:** housing, affordable housing, sustainable housing, low and middle-income earners, prefabricated construction, mass customization design

#### **1. Introduction**

Housing cannot be seen only as just a roof over ones head as it has become a component of man's evolvement and development. Virtually all human activities on planet earth revolves around a house. Housing is widely accepted as one of the indices through which the welfare of humans can be measured [1]. Similarly, housing has equally been reported as a major contributor of human development, especially in the areas of employment generation and the development of the economy of nations. Sharifzai et al. [2] reported that housing is a major indicator of sustainable development in the society. Sustainable development itself is categorized into: social, economic and environmental development. In social development, housing does not only provide shelter but also offers a sense of protection to occupants as having a house is also considered as the ultimate plan in a family's lifetime. In economic development, housing generates significant contribution to the construction industry sector which leads to increase the GDP of a country annually [3]. In environmental development,

housing should be liable to reduce a green house gas emission, optimize energy usage and material and also improve waste management. However, in spite of the benefits of building and living in sustainable houses, reports have shown that sustainable houses are in gross undersupply especially among low and middle-income earners across the globe.

Low income earners are considered those whose household's disposable money income per consumption unit is lower than 60 percent of the equivalent median money income of all households. The proportion of the population falling below this income limit is called the low in come rate [4]. Low income economies as explained by Adabre and Chan, [5] are countries with GNI per capita, especially when calculated by the World Bank Atlas method, of \$1045 or less in 2014 while Middle-income economies are countries with a GNI per capita, of more than \$1045 but less than \$12,736. Middle-income earners are those with average income within the overall population of a country. Low and Middle Income Countries are the countries identified by the Organization for Economic Co-operation and Development as having low-income or middle-income economies, as may be updated from time-to-time by the OECD [6].

Similarly, Ismail et al. [7] reported that the population of the homeless among low and middle income earners around the world stands at 863 million and fast approaching a billion because they reside in shanty towns and informal settlements. Amoatey et al. [8] affirmed that more than 61.7% of the population of Africa are homeless. A recent study conducted by Igwe et al. [9] in Nigeria affirmed that between 17 and 20 million Nigerians are homeless. Evidence from research indicates that the low income earners are among the heaviest sufferers of these housing shortages [10–13]. The studies shows that the problem of housing shortages and inadequacies is far worse for low and middle income earners in developing nations like Nigeria. Low and middleincome earners which constitute over 90% of the population in Nigeria are displaced with respect to housing as a result of their inability to afford the cost (rental, building or outright purchase) of housing occasioned by the increasing costs of building materials, deficient policies of housing, cost of land for housing development, increased interests and inflation rates among others [14–16]. Goh et al. [17] reported that in Malaysia demand for houses has exceeded 37,000 units nationwide in 2015. Also in Kenya, housing market price underwent massive price expansion over the past fifteen years which it continues to grow annually [13]. In South Africa, Kutty, [18] reported that it has become difficult for low - middle income households to buy property when as house prices are becoming higher by the day.

Sustainable affordable housing emerged from of the integration of the aspects of sustainable housing into affordable housing. Sustainable housing according to Nubi and Afe, [19] originated from the concept of sustainable development. Sustainable development as a concept was reported to have emerged from the report titled "Our Common Future" of the United Nations World Commission on Environment and Development (WCED) [20]. The WCED report which is popularly referred to as the Brundtland Report defined sustainable development as that type of development that is made for securing present generational needs of the people while conserving the capacities and capabilities of incoming generations to meeting their own needs when they arise [4]. In order to secure the needs of the present generation and also guarantee the capability of addressing the needs of future generations as contained in the WCED report, sustainable housing need to achieve social, environment and economic balance in the pursuance of developments [21].

Affordable housing are usually housing units which a family group or group of families can acquire within a given period of time, especially within 15 to 30 years [22].

#### *Perspective Chapter: Achieving Sustainable Housing for Low and Middle-Income Earners DOI: http://dx.doi.org/10.5772/intechopen.111870*

According to Nwaba and Kalu, [23], affordable housing are small housing units that use low cost materials and built on cheap land at the edge of the city. Integration of affordable and sustainable housing is the combination of housing that can be owned at minimal price, considers safety, allows for healthy living, and covers with sustainable aspects. The construction of houses that enables low and middle income people to gain affordable homes requires the adoption of cost-effective, innovative and environmentally friendly housing technologies [24]. The houses should be built, affordable and equipped with all of the elements of healthy living, learning, and working.

The measurement of housing affordability is different between countries and regions but the most accepted measurement is the ratio between a household's' income and the housing cost. The most acceptable practice around the world in measuring affordable housing include considering housing cost at a value less than 30% of the household income of the occupants [25]. Thus, affordable housing cost is not more than 30% of the households income. In sustainability, housing quality should is major principle in designing and building houses because sustainable development is important for achieving the required balance between human activities and nature without jeopardizing social and economic systems for future generations. Thus, sustainable housing should be socially, economically, environmentally and technically feasible [26]. Sustainable houses should be made to be easily accessible to all and sundry. It should be well equipped with every elements of healthy living, cost-effective and constructed within a well-connected neighborhood to enhance the quality of life housing development which is essential from the economic, socio- psychological and environmental perspectives.

Many developed and developing countries around the globe view sustainable housing development as unaffordable for low-middle income families and this makes integrating sustainable aspects in providing affordable housing quite challenging. Failure to improve housing affordability will affect long- term economic development, urban development fatality rate and intergenerational equity. Thus, the aim of this paper is to highlight the challenges faced in integrating affordable, sustainable housing and strategies for solving sustainable affordable housing challenges among low and middle-income earners through extensive literature review.

#### **2. The challenges of integrating affordable, sustainable housing among low and middle-income earners**

It has been observed that the phenomenal rise in population, spontaneous increase in size of most Nigerian cities and other developing countries of the world have led to acute shortage of decent and affordable housing units. These have led to numerous problems in the urban centers such as overcrowding, deplorable environment, poor living conditions, inadequate infrastructure, homelessness, and so on. It is a critical challenge to governance to provide adequate and sustainable housing delivery towards progressive urbanization in Nigeria and many other developing countries of the world. Some of the challenges are enumerated as follows:

#### **2.1 Institutional challenges**

The government is one of the main institutions that have a major influence over the development of any industry. The government's demand in providing affordable and sustainable housing will put pressure on construction practitioners.

In addition to the socio-economic state of the families, other factors which influence the phenomenon of homeownership worldwide are the government policies which determine the construction practices, selling prices for housing units, the terms and condition for purchase and selling of these houses and the rental policies [27]. In Nigeria such government policies covers how to access to land, how to access to mortgage or finance facilities, how to obtain building permit and other documentation. Policies have a great influence to homeownership in many developing nations. Chukwujekwu, [28] reported the import tax on building materials affect the cost of buildings as building materials constitute over 60 percent of the cost of buildings in Nigeria. Meanwhile, majority of building materials used in the country are imported. Policies on building materials tariff affect homeownership for low-middle income earners in many developing nations of the world including Nigeria. However, developers do not emphasize sustainability issues due to the lack of monitoring and enforcement by the government in most developing countries [29]. They often perceive that environmental protection is the sole responsibility of the government. Government policies in many developing countries including Nigeria are very fragile because many developers often shy away from implementing the sustainable housing concept in their projects. Most sustainable housing development in Nigeria involve a complicated process which takes a long time to gain the approval plans of local councils which discourages most developers from implementing the affordable sustainable housing units.

#### **2.2 Over dependence on foreign/imported building materials**

Sustainable housing requires ecological building materials, energy saving and esthetic design [30]. The adoption of eco-friendly products in many developing countries are quite expensive which makes it difficult to be applied to low-medium cost projects. Many building contractors and stakeholders are facing major difficulties in obtaining green products in the local market due to the non-acceptance of local building materials by the buyers [2]. Developers in most developing countries are demanding green materials from foreign countries because it portrays a higher quality, thus leading to high dependence of imported building materials. This overdependence on imported building materials eventually lead incurrence additional cost building construction processes [31]. The higher cost incurred for importing green materials and technology is a challenge to the shift towards sustainability. Another challenge lies in determining ways to make sustainable housing affordable as there is a belief that each sustainable housing project is usually planned and designed in detail to comply with its target buyers' financial status, interest, and expectations. Bons et al., [14] stated that most a times, target buyers are mostly high income earners and foreigners who can easily own sustainable houses, as these reflect their lifestyle. Thus, many local builders have to deal with local buyers ranging from low, medium-low and medium-high income earners [26].

#### **2.3 Professional challenges**

The lack of urgency to provide affordable and sustainable housing by the government and builders in most developing countries further adds to the challenges. Profits are generated by targeting low medium cost houses which still dominate the industry while developers are comfortable with their business marketability and are reluctant to commit to something new [25]. Many developers are interested to pursue

#### *Perspective Chapter: Achieving Sustainable Housing for Low and Middle-Income Earners DOI: http://dx.doi.org/10.5772/intechopen.111870*

sustainability practices but it will lead to additional project cost. Big developers have greater financial capacity, better experience and, higher commitment as well as the required expertise to pursue sustainable practices [17]. These developers are more aware of sustainability practices by executing proper planning, design and allocation of budget. However, the majority of developers in many developing countries including Nigeria are from medium and small sized companies. Many of these medium and small sized companies are reluctant to devise their own methods in building design and development. They accept the latest technology which may incur little or no additional cost and in most cases, they may accept sustainability practices if consultants can provide a good design within the project budget [3]. These medium and small sized companies are aware of sustainability issues, but they believe sustainable practices may affect their profit margin [4]. Hence, they are able to implement sustainable practices by incorporating sustainable elements in their small or medium projects by focusing on the design and orientation of houses, providing more green spaces and improving social needs through the upgrading of facilities.

#### **2.4 Technological challenges**

In developing countries of the world, the implementation of sustainable technologies is still at an early stage where specifications and other contract documents have not been documented properly [23]. These challenges make construction practitioners delay the implementation of affordable sustainable practices in housing development. The construction of affordable and sustainable housing units for low and middle income earners requires expertise qualified developers. However, the local knowledge for incorporating green technology and sustainable practices in building construction in Nigeria is still at a developmental stage. This has resulted to just a few handful of builders integrating the affordability and sustainability concept in their building projects [5]. Also as a result of lack of qualified expertise in sustainable construction, many developers in Nigeria are resorting to hiring of foreign expertise to help in implementing sustainable construction practices. Unfortunately, this is posing a hindrance to the local expertise to develop their skills, increase the dependence to foreign experts and incur additional cost. The difficulties of obtaining green technology and materials from the local market in many cases has lead the developers to import green products, which bring about the increase of product costs [17]. Imported green products are mostly produced based on their origin countries' climate which is mostly is different from climate of most developing countries. So local developers have to request for custom-made products to suit the local climate which usually add to the cost, on top of the delivery expenses.

#### **3. Strategies for solving sustainable affordable housing challenges among low and middle-income earners**

#### **3.1 Institutional strategies**

A key institutional strategy of sustainable affordable housing in developing countries is to empower the private sector in the delivery of mass housing as recommended in the enabling approach [32, 33]. The studies stated that with the involvement of the private sector, issues like corruption, politicization that have held the housing sector aback can be addressed. The continuous review as well as updating of housing policies in accordance with existing realities as recommended by sustainable affordable housing practices will also help to address the low-income earners housing needs. A sound housing policy is an all-encompassing housing document because it addresses issues related to land for housing, building materials, housing types, all income groups and many more.

Additionally, a key institutional strategy of sustainable affordable housing is centered on a procurement process that is effective and transparent [23]. The incidences of favoritism, incompetence and undue desire for profit can be addressed with the adoption of a transparent and effective procurement process in the building sector. This will ensure a smooth transition of government initiated housing units to the low and income earners. A lot of cost will also be saved when a transparent and effective procurement process is in place. Studies from Adegun et al. [34] shows that a lot of time and resources can be saved by decentralizing and shifting building project approvals to local authorities, as it would serve as an incentive to local developers. The overall goal delivering more housing units to the low and middle-income earners will be achieved.

#### **3.2 Technological innovation**

The continuous rise in the cost of building materials coupled with the degradation of the environment due to over exploitation which is often occasioned by developmental activities calls for the need to develop and upgrade local resources to sustainable standards. An important technological strategy of sustainable affordable housing should be on the promotion of the use of reusable, renewable and recyclable materials [35]. Through this, the environment shall be further conserved and the incidences of disaster can be further managed. As a way forward, Gooding, [36] stated that there is need to promote technological innovation among building stakeholders in order to ensure sustainable affordable housing for low-middle income earners. There is need for promotion, growth and development of local and rudimentary technologies which is a technological strategy of sustainable affordable housing, [37]. By promoting the development and growth of local technology, the scarcity of skilled labor can be addressed while direct employments can as also be created. The huge finances spent by developing countries on hiring and maintaining foreign building experts will be saved. As a result, housing prices will drastically reduce thereby increasing the lowincome earners access to housing.

#### **3.3 Environmental strategies**

The building and construction industry contributes nearly one third of Global Greenhouse Gas (GHG) Emissions which has led to serious discomfort both in and within the built environment [6]. Low and middle-income countries finds themselves in the middle of this discomfort and even suffer more discomfort as a result of the inadequate situation of their dwellings. Against this backdrop, Twumasi et al., [38] called for the integration of energy efficiency construction practices in developing new projects. The environmental strategy of sustainable affordable housing will help to promote energy conservation through the use of energy efficient lighting systems, solar heating technologies, energy efficient heating systems, ventilation and air condition systems, installation of water efficient appliances improved rain water harvesting technologies and improvements of the housing envelops generally [39, 40]. Although these practices can increase the housing cost and make housing units

#### *Perspective Chapter: Achieving Sustainable Housing for Low and Middle-Income Earners DOI: http://dx.doi.org/10.5772/intechopen.111870*

unaffordable to the low and middle-income earners, the introduction of an incentive driven housing market, can make the houses to be affordable to low and middleincome earners. Murphy, [41] supported by stating that the adoption of current energy conservation strategies will lead to up 80% reduction in energy consumption in buildings. This will certainly lead to more comfort in both indoors and outdoors environment for the low-income earners.

Furthermore, there is need for promotion and use of local resources among low and middle income countries [42, 43]. Sustainable affordable housing through its environmental strategy, encourages the usage of local resources in the form of tax reliefs and incentives to developers. The development and usage of local resources by Nigerian developers will eventually lead to a drastic decline in the price of imported building materials in the country. Thus, making the entire cost of housing units affordable to the low and middle-income earners which will also promote job creation.

#### **3.4 Economic strategies**

Most countries in the world are empowering the private sector with the responsibility of the provision of housing while the government of these countries act as an enabler and promoter. The development of housing in Nigeria and in most developing countries is hampered by the unavailability of incentives to private investors and developers. Onu, and Onu, [44] confirmed that private sector developers are profit oriented hence, most of their outputs are unaffordable to the low and middleincome earners. The burden that the cost of housing comes with are transferred by the developers and investors to the households through rent or outright purchase thus making the low and middle-income earners unable to access the available housing units [45]. The strategy of providing investors/developers with incentives (loans, tax rebates etc.) can help address the challenge and by extension, grant the low and middle-income earners greater access to housing. Incentives through flexibility of building designs and construction will help to motivate the builders to construct more affordable housing units with lower prices for the low and middle-income earners.

The poor financial status of low and middle-income earners in most developing countries especially Nigeria has also been reported as one of the reasons why housing is in limited supply to these set of people [46]. Studies show that prices of most housing units are outside the reach of many low and middle-income earners as a result of their poor and weak financial status. However, the recent provision of housing subsidies in the form of loans and mortgages at lower interest rates by the Nigerian government to low and middle-income households has been well accepted praised around the country [43]. Similarly, Garde, [46] noted that the economic focus of sustainable affordable housing is to provide households with incentives in the form of reduced transportation as well as other non-housing costs. In general, the provision of financial incentives will cushion the economic power of the low and middleincome earners thereby resulting into better housing for them.

#### **3.5 Social strategies**

The incidence of poor maintenance culture and abandoned management of public facilities has also been reported as a challenge limiting the low and middle-income earners access to adequate housing globally [42, 47]. Poor maintenance has led to an increased proportion of aged and deficient infrastructures especially in many

developing countries [33]. These aged and deficient infrastructures are unfortunately home to low-income earners. Roumboutsos, and Macário, [32] noted that retrofitting of aged infrastructures to sustainable affordable standards is less costly and more economical compared to outright project demolition and reconstruction. The studies added that through the retrofitting of aged infrastructures which is one of the social strategies of sustainable affordable housing, the facades of the infrastructures are retained, more employments are created while an almost 80% reduction in energy usage can be achieved thereby boosting the low-income earners housing conditions.

Low and middle-income earners as a result of their low financial status are confined/ restricted to city/urban outskirts where infrastructural facilities are absent thus making their housing conditions more like slums. However, Murphy, [41] reported that reduction and elimination of income/wealth segregation through the promotion of social capital, inclusion and cohesion is one of the social strategies of sustainable affordable housing. Social cohesion brings about a sense of belonging, social solidarity and emphasizes on the need to interact within families and communities. Additionally, inclusion promote easy access of households and families to resources and promotes efficient participation and involvement of the households in economic, political and social activities within the community. All of these put together can foster the relationship as well as inter relationship between the low-income, middle income and the high income households thereby reducing drastically, the incidence of income/wealth segregation.

#### **4. Impacts of applying prefabricated systems to the low-middle family homes**

Prefabrication is a method of construction where the elements of a building, ranging in scale from a component to a complete building, are manufactured at some distance from the final location. These elements are then purchased and carried to the final location where they are assembled and normally attached to pre-prepared foundations. Prefabrication is the production of housing or housing components using factory mechanization. The factory setting enhances affordability through a combination of bulk purchase of materials and mass production assembly techniques. Prefabrication can take one of three forms namely; prefabricated housing components, modular housing, and manufactured housing.

The prefabrication of housing components consist of the separate production of components such as windows, doors, and cabinets. Separate production of such housing components helps in keeping costs down by reducing on-site construction and high cost labor. Modular housing involves the prefabrication of sections of housing that are then assembled on-site thereby reducing on-site labor costs. Modular housing is based on prefabricated, factory-produced, easy-to-transport modular units, which minimize the cost of production. Final structures are designed from the inside out using a series of standard modules of use. Such housing units from these modules have the potential to be configured in a variety of ways, according to the specific requirement of the site or client. Manufactured housing are housing units which are specially produced in factories using unique specification, transported and eventually assembled onsite for the clients [48]. Manufactured housing which are fully built in the factory and today's structures are virtually indistinguishable from their site-built counterpart. Entire houses, containing the same amenities as site built homes, are shipped to the site and placed on a permanent foundation. Manufactured housing is durable, desirable and a viable form of affordable housing.

#### *Perspective Chapter: Achieving Sustainable Housing for Low and Middle-Income Earners DOI: http://dx.doi.org/10.5772/intechopen.111870*

In Nigerian cities, the low and middle income earners suffers from high housing costs and poor service availability with the subsequent impact on other features of economic and over-all well-being. The main characteristics of the Nigerian housing system is marred with long waiting lists, high rents, thousands homeless, millions living in insecure or unsuitable dwellings and a generation of young people priced out of the housing market [49]. Housing supply is failing to keep up with demand while home prices nationwide are rising at twice the rate of incomes and three times the rate of inflation. The affordable housing crisis continues to be a major problem in Nigeria and in most developing nations of the world. This dysfunction has forced the low and middle-income income earners to secure housing outside formal housing provision. However, the fact shows that, conventional construction process could not minimize the high demand of houses due to affordable cost within short time and quality production. Any strategy to address this challenge will need to take into account the particular constraints linked to developing societies. In fact, the need of alternative construction process is the best solution to address these and other related challenges and build sustainable housing for the majority of the population.

The difference in the levels of development and distribution of economic opportunities has resulted in rural–urban drift. People seeking a better living and employment opportunities migrate from rural setting to urban areas thereby increasing population growth. The migrant furthermore, are unemployed and poorly housed set of urban residents. The process of urbanization in many Nigerian cities has resulted in low and middle-income migrants, occupying the urban slums and also seeking to solve their problem of accommodation informally. They are now become dominant and, in most cases, transforming the city to meet their needs, more often in a conflict and substandard housing. Therefore, the alternate options should also lead to building massive houses in a high speed at a less costly and quality materials and also preserve natural resources and energy efficient.

#### **5. Benefits of applying prefabricated systems to the low-middle family homes**

Based on available literature, some of the advantages of the integration of prefabricated housing units for low and middle-income earners in Nigeria include the following:

a.**Reliance on local material:** The availability of indigenous material such as clay, bamboo, rafter, sharp sands is an advantage for housing provision. It has been confirmed that locally produced building material can replace the expensive imported materials. Also, it has been reported that those locally produced materials also exhibit, functionality, esthetic, durability and structural stability that enhance sustainable buildings. Cost of building with local materials cost less, than using conventional material, also local building material are affordable and cheap. Arumala, and Gondal, [50] reported that earth is one of the oldest building materials readily available and very cheap among others. Normally local building materials are not bought, the cost incurred in obtaining them are for only those who will fetch the material e.g. hiring people to cut palm font, dig earth and cut bamboo. This makes it cheap and affordable for obtaining local material for building purpose.


#### **6. Impacts of applying mass customization design to the low-middle family homes**

Mass customization is a system that uses information technology, flexible processes, and organizational structures to deliver a wide range of products and services that meet specific needs of individual customers at a cost near that of mass-produced items. In housing, individual customization is traditionally seen as hiring an architect to creatively design a unique home, ideal for the family. Mass customization in housing is a combination of two strategies; mass housing production and individual customization of housing units. Mass housing production, on the other hand, is when large numbers of identical homes are built and then sold for much less than the uniquely designed homes. Individual customization units is a uniquely designed product that better fit the user's needs with mass production efficiency and costs. It is being adopted in many housing contexts worldwide to provide families with dwellings that suit their individual needs at affordable costs.

Mass customization of housing has been linked to environmental and social sustainability. By providing dwellings that better suit the individual needs of the family, there is less need for renovations and the waste it creates. Furthermore, construction for mass customization often adopts practices, such as prefabrication, which also reduce waste and water and energy consumption. The custom home also increases the users' sense of identity and ownership towards it. However, a drawback of this process is the lack of flexibility in terms of considering requirements of different household profiles especially for low and middle-income earners. Similar to other developing countries, such as Ghana and Kenya most Nigerian housing programs for the low and middle-income earners rely on repetition and high standardization of products with the aim of keeping costs low. Such a standardization also allows for less complicated contractual and financial procedures, contributing to the economy

#### *Perspective Chapter: Achieving Sustainable Housing for Low and Middle-Income Earners DOI: http://dx.doi.org/10.5772/intechopen.111870*

of scale. However, the ability to deliver houses that meet customers' needs in Nigeria while maintaining production efficiency has been a long debate in the house-building industry. This is because most developers also want to benefit from economies of scale by having a high degree of repetition. Thus, applying mass customization ideas to the building sector seems to be an opportunity to accommodate the trade-off between variety and costs.

Government as is often the case in Nigeria always tries to solve the social problems of housing; it does this through the formulation of policies and their subsequent implementation. Jibril and Garba, [51] stated that the failure of the 1991 National Housing Policy was the repetition of the same house type throughout major cities across country. While Akinkunmi, [52] agreed with this view, it stated that the recognition of the failure of Policy prompted the federal government to formulate a New National Housing Policy of 2002 that sought to ensure that Nigerians have access to decent, safe and affordable housing through private initiative. This policy signaled the growth of speculative house building in urban areas and cities in an attempt to meet the set goals. Since then there have not been any meaningful efforts to develop or upgrade the building construction practices in the country especially in the area of mass customization.

#### **7. Benefits of applying mass customization design for low and middle-income family homes in Nigeria**

There are several benefits that could be derived from providing mass customized housing units for the low and middle-income earners in Nigeria; some of them are discussed below;


#### **8. Conclusion**

One of the greatest challenges facing developing nations is the provision of infrastructure to enhance construction of sustainable houses for low and middleincome earners. Also, the responsiveness of the construction industry to the preservation of natural resources for the benefits of future generation has been very poor in developing countries. There is the demand for sustainable shelters to house the growing population of people, especially among low and middle-income earners. Building energy efficient houses does not only contribute to better living conditions, but also a better environment thereby culminating into creating sustainable communities. Therefore effective adoption and implementation of the sustainable strategies for providing affordable housing as discussed in this paper will go a long way in helping low and middle-income earners in affording decent sustainable houses.

Mass customization is a development strategy that stands for the ability to develop high value-added housing units for clients or building occupants within short period of time at relatively low costs. Prefabrication on the other hand is the production of housing units or housing components using factory mechanization which enhances affordability through a combination of bulk purchase of materials, mass production assembly techniques which results in keeping costs down by reducing on-site construction. Through mass customization and prefabricated construction, construction companies can use industrialization techniques to utilize the benefits of industrialization without compromising the opportunity to customize the offering to the customer. The adoption of mass customization and prefabricated construction by

#### *Perspective Chapter: Achieving Sustainable Housing for Low and Middle-Income Earners DOI: http://dx.doi.org/10.5772/intechopen.111870*

developers in many developing countries will help to lower unit cost, increase quality, and provide affordable sustainable housing units for the low and middle-income earners. Therefore, mass customization and prefabricated construction techniques should be widely promoted and adopted especially among developing nations like Nigeria so as to offer the low and middle-income families with dwellings that suit their individual needs at affordable costs.

### **Author details**

Godwin Keres Okereke and Victor Arinzechukwu Okanya\* Department of Industrial Technical Education, University of Nigeria, Nsukka, Enugu State, Nigeria

\*Address all correspondence to: arinze.okanya@unn.edu.ng; arinzeokanya@gmail.com

© 2023 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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#### **Chapter 3**

## Waste Management for Sustainability in the Built Environment

*Hyginus Osita Omeje and Victor Arinzechukwu Okanya*

#### **Abstract**

Wastes are unwanted, undesirable, or unusable materials. Waste is any substance discarded after primary use or may be worthless, defective, and regarded as having little or no use. A by-product and, by contrast, a joint product of relatively minor economic value. Waste management or waste disposal includes the processes and actions required to manage waste, namely preservation, recycling, and reuse from its collection point to its final disposal. Waste generated from construction sites is not supposed to constitute problems for the built environment. Sustainable construction waste management is becoming a reality because of increased awareness and education to reduce/recycle/reuse wastes, provision of collection and recycling points, and improved techniques for reusing construction materials. This chapter will focus on reducing, reusing, recycling, and recovery efforts or the 4R waste management approach for a sustainable built environment. This chapter also describes waste management practices, their benefits, and the effect of prefabricated constructions and mass customization design approaches on waste reduction or control.

**Keywords:** waste management, sustainable waste management, waste reduction, waste reuse, waste recycling, waste recovery, and built environment

#### **1. Introduction**

#### **1.1 Construction waste management**

Waste generation in the construction industry is considered to be one of the major contributors to total waste production, generating around 36% of the total solid waste, resulting in 2.5–3.5 billion tonnes each year around the world [1]. The enormous generation of Construction Waste (CW) presents a significant challenge to the sustainability of the construction industry, the country's economy at large, and environmental sustainability worldwide. Waste in construction is identified in different ways in the literature. For instance, [2] defined waste as a material that should be moved from where it was generated to another location due to damage, excess, and non-use. These materials may not be used specifically due to non-compliance with given specifications or simply because they are by-products of the construction process. This definition is limited to waste materials that are generated during the

construction process [3]. However, it provides a more detailed definition including waste that can be generated from other construction stages/phases. They stated that construction site waste comes in the form of building debris, rubble, earth, concrete, steel, timber, and mixed site clearance materials, which may be various construction activities such as land excavation, site clearing, demolition exercises, and building renovation activities. This simply means that waste materials are made of inert and organic materials. Notably, these definitions refer only to material waste; however, [4] defined construction waste as material, labor, and machinery waste, which may lead to loss of time, cost, and quality. The definitions above prove that construction projects have different types of waste. One of the purpose of this paper is to identify construction waste components and to know which type is going to be focused upon and why.

Various types of waste are generated throughout the construction project. The amount and classification of these wastes depend on different issues, such as the nature and the stage of the construction project and the methods of construction. Solid waste from construction projects often comprises a mixture of inert and noninert materials. These inert materials such as such as concrete, bricks, ceramics, plaster, asphalt, aggregate, rock or rubble, and soil, are components that rarely participate in chemical reactions under normal circumstances. The ferrous and non-ferrous metal, timber, plastic, glass, paper, cardboard, wallboard, and other organic materials are examples of non-inert materials that readily engage in chemical reactions.

#### **2. The 4R approaches to improving construction waste management practices**

The construction industry is flourishing worldwide at a great pace, driven by population growth, urbanization, and increased need for dwellings, business sites, and commercial spaces. The built environment, which is also a major component of the construction industry, is not left out in this trend. The resultant effect means that there is a serious challenge to implement sustainable waste management in the construction industry. Waste management, according to [5], comprises all the activities involved in collecting, transporting, processing, managing, monitoring, and disposing of various waste materials. Observing sustainability is very crucial in waste disposal so that the waste materials can be managed in an efficient manner instead of dumping them in landfills. It also entails curtailing the generation and disposal of materials in a way that averts adverse environmental effects [6]. The authors further explained that waste can be reduced, and if generated, possible reuse and recycling are engaged while disposal comes as a last option.

Sustainable waste management comprises collecting waste materials, transporting waste materials, valorization, and disposal of various waste materials in a manner that does not harm the environment or affect human health negatively or future generations [7]. Sustainable waste management includes all processes involved in the organization of waste management, from production to the final treatment. It also involves the transition from the traditional make-use-dispose traditional practices to a more circular economy. In a circular economy, waste returns to the production cycle, either as new raw materials, energy, or a new product [8]. The major goal of sustainable waste management is to reduce the amount of natural resources consumed, reuse the materials taken from nature as much as possible, and create as minimal waste as possible. It is not only the duty of waste management contractors and companies to

#### *Waste Management for Sustainability in the Built Environment DOI: http://dx.doi.org/10.5772/intechopen.113371*

ensure sustainable collection and management of construction wastes responsibly but also individuals doing their own DIY projects at home. It is also the responsibility of all building stakeholders to maintain sustainability for the benefit of the built environment as well as future generations [9]. Without a concerted effort to collect, recycle, and dispose of waste properly, there is a real danger to the environment that will eventually spill over to people, vegetation, and wildlife. Ecological and environmental conditions around cities are put under pressure as there is an increase in transportation distances, and protection and quality of life diminish, which results in a decline of sustainable commitment and behavior of users. Rondinel-Oviedo [2] noted that resource reduction strategies and integrated waste management in close collaboration with construction stakeholders, urban planners, and infrastructure developers are the basis for achieving environmental improvement in the built environment.

A well-functioning sustainable waste management system should incorporate feedback loops, focus on processes, embody adaptability, and divert wastes from the disposal. Sustainable waste management, therefore, helps improve the air and water quality by creating jobs and improving waste management methods, which lessen the impact of human activities on the environment. It also helps to improve overall human life by reducing food wastage keeping environmental costs at a minimum while preventing poor human health conditions. The role of education can also bring about a positive behavioral change toward sustainable waste management, especially in the built environment.

More than half of the world's population have little or no access to good waste collection and disposal systems. Illegal waste dump grounds are over 40% of global waste [10]. The lack of waste facilities is not the only major challenge, as inadequate information contributes to sustainable waste collection and safe disposal. It starts with proper education of people on waste reduction, reusing, recycling, and waste recovery efforts, which can be simply known as the 4R approach. Through proper education and information campaigns, people will respond to changes in behavior and attitudes toward waste management. This will enhance awareness of the benefits of waste reduction, segregation, collection, reusing, and recycling, thus becoming a collective and conscious effort.

Reducing simply means efforts made to decrease or lessen the amount of waste produced within the built environment. Waste reduction, according to [4], is using less material and energy to minimize waste generation and preserve natural resources. Waste reduction includes reusing products such as plastic and glass containers and purchasing more durable products. Eyeglasses, clothing, and other used materials can be donated to help reduce the amount of material manufactured overall. Pollution as well as waste can also be reduced by purchasing products that replace hazardous materials with biodegradable ingredients [11]. Waste reduction can lead to several environmental benefits, greater efficiency in manufacturing and utilization of goods, leading to less energy consumption. More natural resources are preserved, less solid waste ends up in landfills, while products using less hazardous materials are reused due to waste reduction. Waste reduction also contributes to economic savings because fewer materials and less energy are used when adopting waste-reduction processes. Instead of engaging in the traditional cradle-to-grave procedure, a cradle-to-cradle approach is incorporated where products are not used for a finite time. Instead of disposing of materials or the components of material after a single use, these materials can be converted to other useful purposes [12]. This can also be known as a flow of materials from one phase or use to another. Such an approach can also be adopted in the construction industry or between organizations that may or may not be related

cooperatively. For instance, a cotton manufacturer can send some unwanted scraps to an upholsterer, who uses the scraps as stuffing in chairs. When the life span of the chair is reached, the materials can be returned to the manufacturer, who reuses the parts with endurance. The damaged upholstery, created initially using non-hazardous materials, is sold to a local farmer who composts it. This way, waste-disposal costs are reduced as fewer materials end up as waste, while money is also saved through reduced purchasing. Several ways of practicing waste reduction in the construction environment include reusing products.

Waste reusing is the practice of using a waste material over and over again in its current form. Waste reusing entails taking old or unwanted items that one might otherwise have thrown away and finding a new use for them [13]. Waste reuse, according to [11], is the action or practice of using a waste item to fulfill a different function such as reusing file folders instead of disposing of them after one use or reusing water bottles for storing other liquids after using them to store water. Another example of waste reuse includes using both sides of paper in photocopying to minimize waste and giving out materials that may seem useless, but that another party may find valuable. Waste reuse ensures that waste does not have to be further treated or processed before it is put to good use while recycling/composting requires processing to take place to turn waste material into usable resources. The essence of reuse is to preserve some or all of the energy and materials that went into making such items [3]. Construction stakeholders should embrace the practice of reuse by finding alternate uses for waste items rather than disposing of them. Some common examples of waste reuse include donating used household items like books, magazines, clothing, kitchen wares, etc., to people who may use them for other services. It may also include using empty food containers to store leftovers or reusing plastic grocery sacks as trash containers. Another example is a chair manufacturer who may have no internal use for the scrap upholstery left over after recycling, and this simply means that there will be more durable parts of the used chairs. A good arrangement between the carpenter and the local farmer will allow the scraps to be used once again, benefiting the farmer by adding to his compost.

Waste recycling involves recovering and reprocessing waste materials for use in new products. It includes collecting waste materials, processing or manufacturing into new products, and purchasing those products [1]. Waste materials that can be recycled are usually made from iron and steel scrap, aluminum cans, glass bottles, paper, wood, and plastics. Most waste products can be recycled and reused as substitutes for raw materials from scarce natural resources such as fossil fuel, natural gas, coal, trees, and other mineral ores. Recycling can help to reduce the rate at which solid wastes are deposited in landfills. Recycling also reduces the amount of air, water, and land pollution resulting from waste disposal.

Waste recovery is the extraction of waste materials or energy from waste for further use or processing, including, but not limited to, making materials into compost [13]. Waste recovery, according to [12], is the process of using wastes as an input material to create valuable products as new outputs. Waste recovery is an operation where some waste materials serve some useful purpose by replacing other materials that would otherwise have been used to fulfill a particular function. The benefit of waste recovery is that it reduces the amount of waste generated in the built environment, thus reducing the need for landfill space, and also helps to optimize the values created from waste. Waste recovery often delays the process of using raw materials to produce new materials. Materials obtained from municipal solid waste, construction, demolition, commercial, and industrial waste are often used to recover resources for

#### *Waste Management for Sustainability in the Built Environment DOI: http://dx.doi.org/10.5772/intechopen.113371*

producing new materials. For instance, plastic, paper, aluminum, glass, and metal can be found in waste and retrieved for use and other purposes.

Waste recovery is part of a circular economy in which the extraction of both natural resources and waste generation is reduced to the barest minimum. It also involves waste materials and products being redesigned more sustainably for durability, reuse, reparability, remanufacturing, and recycling. Lifecycle analysis (LCA) can be used to compare the resource recovery potential of different treatment technologies [3]. Resource recovery can be employed in the process of sanitation, which includes processes and activities of recovering resources trapped in wastewater and human excreta (urine and feces). The term "toilet resources" has come into use recently, which may include organic matter, energy and water, and nutrients such as nitrogen and phosphorus [14]. This concept is also referred to as ecological sanitation. Separation of liquid wastes such as keeping urine separate from feces (as in urine diversion toilets) and keeping greywater and blackwater separate can help make resource recovery simpler. A sustainable waste management plan should always include recovery as a priority strategy for its treatment. However, sometimes it may not be feasible to recover and recycle discarded materials, which are considered nonrecoverable waste, and they mostly end up in dumpsites and landfills. It is imperative for countries to introduce regulations on these types of waste, which will require companies to supervise disposal operations by adopting the necessary measures to protect human health and the built environment (**Figure 1**).

#### **2.1 Sustainable waste management practices in the built environment: economic and social benefits**

Man-made structures, features, and facilities are collectively known as the built environment. Built environment, according to [9], are man-made surroundings that provide settings for human activities, which ranges from buildings, parks, green space, and neighborhoods. The built environment includes the buildings, the distribution systems that provide water, electricity, and the roads, and it also consists of

**Figure 1.** *The 4R approaches to waste management hierarchy.*

the bridges and the transportation systems that people use to get from place to place [1]. The construction and the use of facilities within the built environment by the people tend to generate a lot of waste materials. The provision of skip bins, collection containers, and recycling centers dramatically influences how much people and their communities recycle and reuse or dispose of construction waste properly. Finding a sustainable way to manage or dispose of these wastes is paramount to maintaining a healthy environment.

This is why contractors and recycling specialists must put their heads together to minimize construction waste. However, the authors [7] noted that the general awareness of reducing dumping has recently increased as about 35% of construction and demolition waste (CDW) goes to dumpsites and landfills. Construction wastes comprise many toxic materials such as lead, asbestos, and other dangerous substances that can find their way into the soil, groundwater, and the air we breathe. Also, in recent times, stakeholders in the construction industry have recognized that reusing building components and materials in the making or erecting structures is sustainable, which can save costs, too. Most construction materials consist of wood, sticks, steel, concrete, and rubble, which can be compacted and reused for construction purposes. Demolition is carefully considered if renovation can be carried out. Sustainable waste management is a set of practices and strategies used to reduce the negative environmental impacts of waste disposal. It includes reducing waste generated, reusing and recycling materials, and composting organic waste. Sustainable waste management practices can help the built environment to create economic and social benefits through the following ways.

#### *2.1.1 Reducing expenditure*

One of the main benefits of sustainable waste management is the reduction of expenditure. Money-saving opportunities arise from reducing the waste created and reusing or recycling materials. Firms, companies, and business owners can save money by reducing the amount of packaging they use and recycling materials like cardboard and plastic. Companies can also save money on maintenance and operating costs using fewer resources, such as energy and water.

#### *2.1.2 Improvement of environmental health*

Reducing pollution and dangerous chemicals is one of the major aims of sustainable waste management. Reusing materials can reduce the need for new resources, which helps protect the environment from the impacts of resource extraction. Sustainable waste management can also improve air and water quality, improving communities' health.

#### *2.1.3 Economic growth*

Sustainable waste management can create economic growth comprising more waste management opportunities, increased tax revenue for local governments, and support for local businesses. Companies focusing on waste reduction, reuse, and recycling can create more jobs in their communities, and local governments can receive more tax revenue from businesses reducing their waste. Businesses that adopt sustainable waste management practices can support local businesses by buying locally produced and recycled products.

#### *2.1.4 Better community collaboration*

Sustainable waste management practices can also increase community engagement. Communities can become more engaged with waste management practices by providing better access to recycling and composting resources, educating citizens about sustainable practices, and encouraging participation in green initiatives.

#### *2.1.5 Improved resource efficiency*

Reusing and re-purposing materials through sustainable waste management practices can help to reduce the need for new resources and also help conserve materials. Recycling materials like paper, plastic, and metal can also help save resources including reducing the need for new resources or raw materials.

#### *2.1.6 Promotes better health and safety*

Sustainable waste management can also improve health and safety. Reducing the number of toxic chemicals in the environment can help reduce the risks of health problems. Lowering the amount of waste generated will also reduce the number of pests and disease-carrying organisms. Improving air and water quality could also lead to improved health and safety of people within the built environment.

#### *2.1.7 Promotes positive social impacts*

Sustainable waste management can also have positive social impacts. These impacts include increased civic pride, improved quality of life, and more equal distribution of resources. Improving air and water quality can improve the quality of life for citizens. More efficient use of resources would lead to more equal distribution of resources, which can help reduce poverty.

#### *2.1.8 Economic rewards*

Sustainable waste management practices within the built environment can also lead to financial benefits. These benefits include tax breaks and incentives, increased access to grants, and reduced insurance premiums. Businesses that reduce their waste can qualify for tax breaks and incentives from local governments. Also, businesses that focus on sustainable waste management can access grants to help cover the costs of sustainable practices (**Figure 2**).

#### **2.2 Constraints to an effective construction waste management**

Construction waste management is considered the most important item for all construction stakeholders worldwide. Creating novel solutions and understanding different sustainable approaches will be required to attain effective and sustainable construction waste management. Increasing the recycling rate for non-hazardous waste materials can be an ambitious target in certain countries, which could contribute to the improvement in the economic and environmental sectors. Sharing best practices, techniques, and barriers among decision-makers and stakeholders

#### *Prefabricated Construction for Sustainability and Mass Customization*

is paramount for developing new policy and strategic frameworks for sustainable waste management. There are so many barriers that hinder the effective implementation of waste management in construction projects, and some of them include the following:

#### *2.2.1 Weak institutional framework*

In most countries, several institutions are involved in waste management, often leading to many institutions reneging on their responsibility for waste management, thinking that another institution would tackle the problem, as there is usually confusion about who is responsible. A weak institutional framework is particularly a major challenge to effective, sustainable waste management in most developing countries, where the institutional arrangements for waste management are weak.

#### *2.2.2 Poor law enforcement*

Most developed countries have a good history of safeguarding the environment by ensuring proper construction of waste management systems with appropriate legislation. However, enacting and enforcing waste management legislation is still a major challenge, especially in developing countries including Nigeria. The non-enforcement and non-compliance with laws governing construction waste management have significantly contributed to poor construction waste management in many developing countries of the world.

#### *2.2.3 Weak regulation*

The regulation of the environment, including construction waste management, is essential to ensuring good environmental governance. However, weak enforcement of environmental regulations in many countries allows construction firms to flout regulations on construction waste management without sanctions.

#### *2.2.4 Weak technological advancement*

When concentrations for greenhouse gas reduction, landfill minimization, and land reclamation are involved, construction waste management technology choices in many countries are increasingly becoming very complicated. This is also partly because the construction waste management sector is evolving into a specialized industry with high technological standards. Thus, engagement with the sector will require in-depth experience, thorough research, and engineering expertise.

#### *2.2.5 Poor human resources*

Human resource is essential for effective waste management, especially the daily operations of construction waste management. Many countries do not have the human resources with the requisite expertise required to function in a construction waste management system effectively.

#### *2.2.6 Insufficient attention paid to construction waste management*

Stakeholders in the construction industry usually focus more on completing the project within budget, expected time, and to the desired quality, to the detriment of the waste that emanates from the construction activities. This has given a bad image to the construction industry, as the improper disposal of construction waste results in far-reaching environmental consequences.

#### *2.2.7 Lack of fundamental data on construction waste management*

Sound waste management requires reliable data on generation rates and composition of the waste. In many developing countries like Nigeria, there is no fundamental data on construction waste management that will inform effective planning for sustainable construction waste management. However, in most developed countries, the available data on construction waste management are woefully inadequate to help in any construction waste planning or management.

### **3. The effect of implementation of prefabricated constructions and mass customization design approach on waste reduction or control**

Prefabrication is a construction process where the bulk of construction activities are shifted from the building site to a remote factory or workshop [15]. Prefabrication involves the process where housing components are manufactured off-site in a factory setting with precise specifications from the architect or engineer. These prefabricated components are then transported to the building site where they are quickly assembled into a cohesive structure. It is an efficient and eco-friendly method of building structures faster while still maintaining quality control because it creates buildings with superior structural integrity in a fraction of the time and cost of traditional building methods. Mass customization is the process of manufacturing customized and personalized building designs for a specific group of people [16]. Mass customization also involves designating adaptable personalized housing units for a specific group of people [17]. Mass customization entails offering housing units that meet the demands

of individual customers but which still can be produced on an industrial and larger scale. Prefabrication construction and mass customization is a rapidly growing manufacturing process that has been embraced by architects, engineers, and construction managers in recent times. However, the continuous development of the construction industry has drastically increased the amount of waste, which not only causes enormous waste of resources but endangers the environment and well-being of building occupants. Thus, the reduction and treatment of construction waste have become a major topic of concern worldwide. Prefabricated constructions and mass customization design approaches can help in waste reduction or control through the following:


*Waste Management for Sustainability in the Built Environment DOI: http://dx.doi.org/10.5772/intechopen.113371*

d.*Offering substantial savings over lifetime*: Prefabricated buildings and mass customization units are mostly designed to be easily dismantled and reused at the end of their lifecycle, helping to reduce waste that may be sent to dumpsites and landfills. Thus, contributing to circular economies that promote long-term sustainability goals for the environment. The efficiency of prefabricated buildings and mass customization units can also offer substantial savings over their lifetime due to their net zero design principles. By adopting the use of renewable energy sources like solar power and geothermal heating/cooling systems, these buildings require less energy from outside sources, resulting in lower utility bills for building occupants over time.

#### **4. Conclusion**

Sustainable waste management practices in the built environment can provide a wide range of benefits to companies, businesses, and communities. These benefits include reducing expenditure, improving environmental health, economic growth, and so on. By adopting sustainable waste management practices in and around the built environment, private houses, homes, companies, businesses, and communities can save money, protect the environment, and create economic and social benefits. Adopting and implementing sustainable waste management practices can help ensure that all occupants of the built environment are more sustainable and resilient now and in the future.

#### **Conflict of interest**

The authors declare no conflict of interest.

#### **Notes/thanks/other declarations**

Thank you for the opportunity given to us to contribute a chapter to your book.

#### **Author details**

Hyginus Osita Omeje and Victor Arinzechukwu Okanya\* Department of Industrial Technical Education, University of Nigeria, Nsukka, Enugu State, Nigeria

\*Address all correspondence to: arinze.okanya@unn.edu.ng

© 2023 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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### Section 2
