Page 63 - GRIHA Manual Volume II - Introduction to National Rating System
P. 63
Sustainable site planning 55
3. Cool/light coloured façades: Building facades behave in a manner similar to the building roofs.
Thus, building facades, constituted out of concrete and steel, absorb more heat than surrounding
environment and add to UHIE. This can be mitigated by using light-coloured surfaces on
the building facades or coating buildings with high albedo paints. Light-coloured surfaces
with high-albedo can lead to a reduction in the energy consumption of the HVAC system of
13
the building by about 7.5%. In high-rise buildings, cool facades have a larger impact than
cool roofs.
4. Green roofs and walls: Besides covering the roofs with high-albedo coating, roofs can also be
covered with roof gardens. These act as insulation for the building and mitigate the UHIE as
they lead to evapo-transpiration, thereby bringing down the temperature of their surroundings.
Green walls cover the building facades in process help in reducing UHIE while simultaneously
adding to the aesthetic appeal of the building and providing insulation to the walls. Both green
roofs and green walls help in reducing energy consumption in the buildings as well. Green roofs
and walls also filter the air and help in reducing air pollution.
5. High-albedo walkways and streets: Streets and walkways should be made of high-albedo
materials. Light-coloured aggregate can be used to making streets and roads. Increase in albedo
of 0.1 decreases the pavement temperature by about 8° F.
6. Shaded surfaces: Besides using high-reflective measures to ensure that minimum radiation is
absorbed, providing shade to surfaces like roads in parking lots help further cut the amount of
radiation being absorbed and helps reduce heat gains. Shaded parking lots and walkways also
provide comfortable spots for people to park their cars and walk under.
7. Pervious paving: Paved surfaces on site should be pervious. This is to minimize storm water
run-off and enhance the local aquifer recharge. Besides this, pervious paving also absorbs
moisture which it can later lose through evaporation and help in reducing ambient air
temperatures in its vicinity.
8. Design paved surfaces like roads and pedestrian walkways for minimum standards than peak
loads: This step reduces the use of construction materials while simultaneously reducing site
disturbance and reducing the impervious area on site.
9. Planting trees: Trees help shade building facades and pavements, thereby reducing heat gain.
Planting trees towards the southern and western facades of the building is especially beneficial in
most part of India. They also help in regulating the UHIE through the process of evapo-transpiration.
It is estimated that an average tree can offer a cooling effect in the atmosphere equivalent to about
14
5 air-conditioners (Santamouris 2001). Thus, trees help in reducing and mitigating UHIE in
multiple ways.
13 Ibid.
14 Santamouris M. 2001. Energy and Climate in the Urban Built Environment, London: James & James Publication
3. Cool/light coloured façades: Building facades behave in a manner similar to the building roofs.
Thus, building facades, constituted out of concrete and steel, absorb more heat than surrounding
environment and add to UHIE. This can be mitigated by using light-coloured surfaces on
the building facades or coating buildings with high albedo paints. Light-coloured surfaces
with high-albedo can lead to a reduction in the energy consumption of the HVAC system of
13
the building by about 7.5%. In high-rise buildings, cool facades have a larger impact than
cool roofs.
4. Green roofs and walls: Besides covering the roofs with high-albedo coating, roofs can also be
covered with roof gardens. These act as insulation for the building and mitigate the UHIE as
they lead to evapo-transpiration, thereby bringing down the temperature of their surroundings.
Green walls cover the building facades in process help in reducing UHIE while simultaneously
adding to the aesthetic appeal of the building and providing insulation to the walls. Both green
roofs and green walls help in reducing energy consumption in the buildings as well. Green roofs
and walls also filter the air and help in reducing air pollution.
5. High-albedo walkways and streets: Streets and walkways should be made of high-albedo
materials. Light-coloured aggregate can be used to making streets and roads. Increase in albedo
of 0.1 decreases the pavement temperature by about 8° F.
6. Shaded surfaces: Besides using high-reflective measures to ensure that minimum radiation is
absorbed, providing shade to surfaces like roads in parking lots help further cut the amount of
radiation being absorbed and helps reduce heat gains. Shaded parking lots and walkways also
provide comfortable spots for people to park their cars and walk under.
7. Pervious paving: Paved surfaces on site should be pervious. This is to minimize storm water
run-off and enhance the local aquifer recharge. Besides this, pervious paving also absorbs
moisture which it can later lose through evaporation and help in reducing ambient air
temperatures in its vicinity.
8. Design paved surfaces like roads and pedestrian walkways for minimum standards than peak
loads: This step reduces the use of construction materials while simultaneously reducing site
disturbance and reducing the impervious area on site.
9. Planting trees: Trees help shade building facades and pavements, thereby reducing heat gain.
Planting trees towards the southern and western facades of the building is especially beneficial in
most part of India. They also help in regulating the UHIE through the process of evapo-transpiration.
It is estimated that an average tree can offer a cooling effect in the atmosphere equivalent to about
14
5 air-conditioners (Santamouris 2001). Thus, trees help in reducing and mitigating UHIE in
multiple ways.
13 Ibid.
14 Santamouris M. 2001. Energy and Climate in the Urban Built Environment, London: James & James Publication
