**3.4 Windbreaks**

The Wind is an important climatic factor that has to be considered in a landscape design. The Windbreak is an effective system used in a landscape to control

**79**

**climatic zones**

*Energy-Efficient Landscape Design*

**Figure 8.**

*DOI: http://dx.doi.org/10.5772/intechopen.94904*

*Wind-shadows created by landscaping. Source: Co-author.*

wind & its impacts. These shelter belts, formed by rows of trees and shrubs can reduce the wind speed or redirect its movement. Properly planted windbreaks in a cold climate can regulate the heat loss & air infiltration by reducing the wind velocity around the building. Plants that can withstand the winter climate conditions have to be selected for windbreak systems. It is an effective technique to use evergreen species as the major constituent of a windbreak composition. They occupy a significant portion of the system as these plant species retain wind-blocking mass in winter. These species can divert cold winds from the buildings & thus reducing the expense for heating. Distance between the tree and building depends upon the tree height. The Optimum distance is usually taken as 1 to 3 times the windbreak height. Distance up to which the wind can be reduced depends upon the height of the tallest row. It is considered to be 30 times the height. The effective distance of a windbreak system is generally indicated based on the windbreak multiplier, which is measured from the middle of the outermost layer of vegetation, downwind, along a line following wind direction. Components of a windbreak system have to be closely spaced to act as a continuous barrier against the wind. It is necessary to consider the final form that plant species will achieve once they get matured. A one-row windbreak system is formed by a single linear row of trees & shrubs. Evergreen plant species are densely planted in a one-row windbreak as these species retain their lower limbs & foliage. Deciduous plants with narrow clowns can be used and these plant species have to be densely planted. Two-row & twin-row windbreaks are composed of two linear rows of trees or shrubs. A single species, a set of 2 species, or a mixture of species can be used to form this windbreak system. Each row of the windbreak has to be densely planted in the same way as in a one-row windbreak. Three-row windbreaks are composed of 3 rows of trees or shrubs. It should include at least one row of dense evergreen trees. Other rows can be either deciduous or evergreen plantings. Shrubs can also be used as a front-row to catch the snow, if necessary. The three-row system provides additional sheltered spaces and there is a possibility for greater diversity. Thus, the three-row windbreak system has more

wildlife value than a single or double-row system (**Figure 8**).

**4. Energy-efficiency through landscaping - techniques for different** 

The mature size of plant species has to be considered in designing the landscape. The growth rate is thus an important factor. Fast-growing plant species may not be a good choice as most of these species have poor strength even though some vines are effective fast-growing species that can be used in landscaping. Man-made

*Design of Cities and Buildings - Sustainability and Resilience in the Built Environment*

Deciduous plants are the best shading devices. They can shed their leaves in

• Advantages - low cost & aesthetical value, glare can be reduced, these plants

• Disadvantages - limited height, diseases can affect growth & slow growth

The east, south-west & south-east sides of a building are usually considered as proper locations for deciduous plants. Deciduous plants may also cause more harm during winter than good in the summer if those plants are not carefully placed on

The Wind is an important climatic factor that has to be considered in a landscape design. The Windbreak is an effective system used in a landscape to control

response to the change in temperature.

*Shading of west walls through landscaping. Source: Authors.*

*Shaded alleys under canopy cover. Source: Co-author.*

the southern side of a building.

**3.4 Windbreaks**

**Figure 6.**

**Figure 7.**

have the ability to cool the air via transpiration.

**78**

**Figure 8.** *Wind-shadows created by landscaping. Source: Co-author.*

wind & its impacts. These shelter belts, formed by rows of trees and shrubs can reduce the wind speed or redirect its movement. Properly planted windbreaks in a cold climate can regulate the heat loss & air infiltration by reducing the wind velocity around the building. Plants that can withstand the winter climate conditions have to be selected for windbreak systems. It is an effective technique to use evergreen species as the major constituent of a windbreak composition. They occupy a significant portion of the system as these plant species retain wind-blocking mass in winter. These species can divert cold winds from the buildings & thus reducing the expense for heating. Distance between the tree and building depends upon the tree height. The Optimum distance is usually taken as 1 to 3 times the windbreak height. Distance up to which the wind can be reduced depends upon the height of the tallest row. It is considered to be 30 times the height. The effective distance of a windbreak system is generally indicated based on the windbreak multiplier, which is measured from the middle of the outermost layer of vegetation, downwind, along a line following wind direction. Components of a windbreak system have to be closely spaced to act as a continuous barrier against the wind. It is necessary to consider the final form that plant species will achieve once they get matured. A one-row windbreak system is formed by a single linear row of trees & shrubs. Evergreen plant species are densely planted in a one-row windbreak as these species retain their lower limbs & foliage. Deciduous plants with narrow clowns can be used and these plant species have to be densely planted. Two-row & twin-row windbreaks are composed of two linear rows of trees or shrubs. A single species, a set of 2 species, or a mixture of species can be used to form this windbreak system. Each row of the windbreak has to be densely planted in the same way as in a one-row windbreak. Three-row windbreaks are composed of 3 rows of trees or shrubs. It should include at least one row of dense evergreen trees. Other rows can be either deciduous or evergreen plantings. Shrubs can also be used as a front-row to catch the snow, if necessary. The three-row system provides additional sheltered spaces and there is a possibility for greater diversity. Thus, the three-row windbreak system has more wildlife value than a single or double-row system (**Figure 8**).
