How City Development Contributes to Heat Stress
We shape our buildings; thereafter they shape us. - Winston Churchill
Several cities in India have breached 50 degrees Celsius. While global factors are contributing to heat wave conditions in India, the built environment of our cities is also intensifying the heat stress. Let’s see how this is happening.
Urban planning in India primarily relies on the Master Plan. Master plans divide city land-uses into zones (e.g., residential, commercial) and restrict, prohibit, or permit the number, types, and features (e.g., plot coverage, height) of buildings. In the late 1980s, the National Commission on Urbanization assessed the master planning approach. They found that master plans were rigid, had been reduced to giving building permissions, and were disconnected from investment flowing into cities.
Post-1991, there was an acute need to make master plans flexible to facilitate higher investment flows into cities. As a result, “growth machines” emerged in various Indian states, driven by state governments. Typical growth machines consisted of corporates, industrial firms, businesses (e.g., retail, entertainment), realtors/builders, business organizations, and industry associations. The primary aim of growth machines was to improve the ‘business climate.’
The growth machines opened master plans to make them dynamic, adaptive and iterative. Some examples include:
Dynamic: Making floor-space index (FSI) flexible (e.g. Maharashtra), or completely doing away with FSI (e.g. erstwhile AP).
Adaptive: Giving exemptions in setbacks, and height to plot owners who gave their land free-of-cost for road widening (e.g. Telangana).
Iterative: Regularizing unauthorized constructions and irregular layouts.
Opening up master plans led to rapid building activity and the development of export promotion zones (EPZ), retail malls, office/business parks, schools, convention centers, sports stadiums, gated housing, riverfront development, professional colleges, industrial complexes, and highways. These high-level development projects delivered unprecedented growth and generated significant employment in Indian cities. But they also made cities hotter.
One key reason is that high development projects are made of concrete, steel, and bitumen, which absorb a lot of heat and warm up cities. Moreover, these buildings are huge, and larger buildings slow the wind, reducing its cooling effect.
Studies show that the temperature difference between different parts of cities can be as much as 5-7 degrees Celsius; night temperatures are higher, and cities cool more slowly at night. All this compounds the heat stress in cities caused by global factors.
We have relied on the master planning approach to shape our cities. As early as the 1980s, the National Commission on Urbanization identified the plans’ inability to keep pace with the times. Post-1991, coalitions of interests emerged to attract investments into the built environment by making land use flexible, relaxing building norms, and creating road networks beyond what master plans mandated.
As the master plans are implicated in the production of heat stress in cities, more master planning is unlikely to ‘solve’ the crisis.
