*Circular Economy in Buildings DOI: http://dx.doi.org/10.5772/intechopen.107098*



### **Table 6.**

*Embodied energy as a function of the number of the floors [44].*

double skin systems involve lower operational energy requirements in all the climate zones, but consume higher embodied energy (**Figure 6**).

They have also experimented with the double-skin façade (U-1.10 W/m<sup>2</sup> K) of "The Shard" in the UK and found that the embodied energy has increased almost double than the typical single-skin façades. Azari and Abbasabadi [11, 43] experimented with the embodied energy of different window systems from cradle to grave and found that wood has the lowest embodied carbon emission. The performance of PVC is completely opposite to the wooden window systems and Aluminum has a high operational and embodied carbon emission rate (**Figure 7**, **Table 7**).

### *3.1.3 Fabric insulation*

In Europe, inorganic fibrous insulations like glass wool and stone wool are dominating the market of insulation materials (almost 60% of the market), and organic foamy materials like polystyrene and polyurethane account are almost 27% of the market. Different glass types, window-to-wall ratio, size, number of glass panes, and frame types are responsible for the embodied carbon emission of windows (**Table 8**).

Therefore, EE studies of tall buildings should be facilitated by comparing available materials and developing inventory databases of building materials and tools that represent tall building construction practices [43] Designer's choice made on all


### **Figure 6.**

*Embodied energy analysis of glazed façade typologies [44].*

### *Circular Economy in Buildings DOI: http://dx.doi.org/10.5772/intechopen.107098*

**Figure 7.** *Embodied energy analysis of glazed façade typologies chart [44].*


### **Table 7.**

*Cradle-to-grave embodied energy and operational energy of different windows [43].*

the materials in the building construction can introduce reductions of 50% of nonrenewable life cycle EE in the buildings (Himpe E et al. 2013). Comparing the embodied energy emission of steel, concrete, and wood, the following results were found.

For the non-zero-energy buildings, the impact of the building services was about 5% of the life cycle EE which is negligible but the impact of the building services


### **Table 8.**

*Embodied energy of insulation panels [43].*

of zero-energy tall buildings rose to 18 and 48%. The area of research on building embodied energy is still a largely unexplored area. Many of the existing studies on EE are subject to inconsistently reported methodologies, poor data quality, lack of technological and geographical representativeness, limitations in the generalizability of results and repeatability of research, etc. [11]. While there exist strong quantitative methodologies for EE estimation in the built environment, the lack of standardized protocols is still a major problem. To reduce the embodied energy of tall buildings and increase material circularity, BIM can assist construction and demolition by providing an accurate number of materials. So that contractors are aware of valuable components which can be used in the process of circular economy.

The embodied energy of building materials is an essential component for calculating the potentialities of the circular economy of building materials. Building materials that have higher embodied energy can be recycled or reused more than materials with lower embodied energy. As a consequence, it is important to investigate and select the building materials which have lower embodied energy and high potential to reuse or recycle several times.
