Cool Roofing Technologies for Achieving Thermal Comfort in Social Housing - India

This activity is providing a variety of cost effective cool roofing options in India, ranging from simple lime wash with adhesives to polyurethane based insulation materials. These low tech options combines with improved ventilation can improve indoor comfort for all sections of society.

Key facts:

Over 100 households with more than 40,000 square feet of roof area have benefited from 13 different cool roofing technologies.

The problem

The Indian government over the last five years has constructed thousands of social housing projects in major cities across the country. These houses provide 300 to 400 square feet of space to the low income families. Due to space constraints, many of these houses are constructed with limited ventilation, making it uncomfortable as the temperature increases. The number of hot days have increased due to climate variability, and low income households are having to deal with health issues like overexposure to heat. The use of inefficient technologies by urban poor and middle class is currently contributing to consumption/wastage of large amounts of water and energy.

The solution

This activity offers several cool roofing options to increase low income households’ comfort level. These strategies also help reduce the energy consumption for cooling. Local climate should be considered before deciding the suitable mitigation strategy or combination of complementary strategies. Strategies include planting trees and vegetation, installing and maintaining green roofs, using white floor tiles on roof and painting roofs with lime wash every year thereby increasing the solar reflectance and decreasing the heat gain and/or using passive cooling systems.

Helping the planet

Cool roofs directly reduce greenhouse gas emissions by conserving electricity for air conditioning therefore emitting less CO2 from power plants. A study found that worldwide reflective roofing will produce a global cooling effect equivalent to offsetting 24 gigatonnes of CO2 over the lifetime of the roofs. This equates to USD 600 billion in savings from CO2 emissions reduction.

Helping people

Smog is created by photochemical reactions of air pollutants and these reactions increase at higher temperatures. Therefore, by reducing the air temperature, cool roofs decrease the rate of smog formation, which improves air quality reducing heat-related and smog-related health issues, including heat stroke and asthma.

Scaling Up

This activity’s cool roofing methods are all cost-effective and can be scaled up across India.