Page 17 - GRIHA Manual Volume III - Introduction to National Rating System
P. 17
10 GRIHA Manual: Volume 3
Figure 7 Provide maximum openings along north and south
4. Shading design
In order to reduce insolation and heat gain, two strategies can be adopted, namely, façade shading
and fenestration shading.
a. Façade shading
It is always advisable to block direct solar radiation at source, that is, before it heats up the building
surface. If the critical surfaces of the proposed building can be shaded externally, then the cooling
load of the building can be reduced drastically. In the orientation analysis, it has been observed
that maximum incident heat gain occurs through the roof, followed by walls to the west and
east. Therefore, these façades need appropriate shading devices that can cut incident radiation
throughout summer. The western and eastern walls of buildings are subject to very low angle solar
radiation due to lower altitude position of the sun, with respect to the wall surface. Therefore, these
walls are difficult to shade with horizontal shading device, and these façades require complete
vertical shading or vertical screening. There are various types of façade-shading strategies, which
can be incorporated in building design such as the following
1. Roof pergola
2. Space frame/ tensile structure
3. Green wall
4. Wall/ window pergola
5. False wall/jaalis
6. Plantation on east and
west sides
Note: Refer Annexure 1 for examples of
facade shading. The design team can
explore more options beyond the list
provided.
b. Fenestration shading
The openings / fenestrations
are the prime source of heat
gain in the building envelope.
Therefore, if façade shading is
not possible, then it becomes Figure 8 Optimized shading device for all seasons
important to shade the
Figure 7 Provide maximum openings along north and south
4. Shading design
In order to reduce insolation and heat gain, two strategies can be adopted, namely, façade shading
and fenestration shading.
a. Façade shading
It is always advisable to block direct solar radiation at source, that is, before it heats up the building
surface. If the critical surfaces of the proposed building can be shaded externally, then the cooling
load of the building can be reduced drastically. In the orientation analysis, it has been observed
that maximum incident heat gain occurs through the roof, followed by walls to the west and
east. Therefore, these façades need appropriate shading devices that can cut incident radiation
throughout summer. The western and eastern walls of buildings are subject to very low angle solar
radiation due to lower altitude position of the sun, with respect to the wall surface. Therefore, these
walls are difficult to shade with horizontal shading device, and these façades require complete
vertical shading or vertical screening. There are various types of façade-shading strategies, which
can be incorporated in building design such as the following
1. Roof pergola
2. Space frame/ tensile structure
3. Green wall
4. Wall/ window pergola
5. False wall/jaalis
6. Plantation on east and
west sides
Note: Refer Annexure 1 for examples of
facade shading. The design team can
explore more options beyond the list
provided.
b. Fenestration shading
The openings / fenestrations
are the prime source of heat
gain in the building envelope.
Therefore, if façade shading is
not possible, then it becomes Figure 8 Optimized shading device for all seasons
important to shade the
