Housing must be climate-resilient

Delhi recorded its second warmest February since 1901, with a mean maximum temperature (MMT) of 27.9 degrees Celsius, eclipsed only by 2006 when MMT was 29.7 degrees, the India Meteorological Department (IMD) said. This happened because of clear skies, caused by fewer western disturbances. The high temperature also led to a slight spike in the power demand. Even though an isolated weather phenomenon led to the rise in February temperatures, there is no doubt that the climate crisis is leading to a warmer world. This is leading to an increase in the demand for cooling, pushing up consumption from coal-fired electricity plants. Air-conditioners (ACs), which use high global warming-potential refrigerants, are also turning cities into heat islands.

To adapt to this reality, India needs to construct buildings that are thermally comfortable; have natural daylight; and proper ventilation. Three principles must be followed — ensuring window shading and ventilation; insulating walls and roofs; and sharing of walls between two buildings. This focus on natural thermal comfort will minimise the use of ACs, and using less/reusing building material will mean less use of natural resources.

To kickstart this green housing revolution, states must adopt the Eco-Niwas Samhita Part I, an energy conservation building code for residential buildings, which was launched by the Bureau of Energy Efficiency in 2018. This sets standards to limit heat gains (for cooling-dominated climates), limit heat loss (for heating-dominated climates), and ensure natural ventilation and daylight potential. Unfortunately, the codes are voluntary, and many states have not dovetailed them into their by-laws.