New Government’s Agenda: Plan them cool

Cities are fast becoming hotspots for environmental action. As they grow to cater to the needs of the expanding urban population, there is an increase in motorisation, concretisation, proliferation of slums and shrinking green and blue spaces. In a warming world, cities suffer due to the urban heat island effect, flooding, water scarcity, improper solid waste management, pollution of air and water and overall deteriorating liveability.

The Centre has taken measures to combat these impacts. For instance, Union Budget 2024-25 allocated Rs 10,400 crore for the Atal Mission for Rejuvenation and Urban Transformation (AMRUT) and Smart Cities Mission; Rs 21,336 crore for metro rail projects; Rs 5,000 crore for the Swachh Bharat Mission; and Rs 80,761 crore for the Pradhan Mantri Awas Yojana (PMAY). The 15th Finance Commission of India and the National Clean Air Programme have also proposed more funds to urban local bodies to tackle some problems.

However, action so far has been slow and is not quite outcome-oriented. Sustainable growth of cities needs measurable indicators that bring tangible results:

Housing support

PMAY or the Housing for All mission has led to the development of millions of affordable housing units. However, these units may not provide thermal comfort, given the lack of criteria for thermal performance. This is confirmed in a 2021 study by Delhi-based Centre for Science and Environment (CSE).

The Affordable Rental Housing Complexes scheme, a sub-programme under PMAY introduced in 2020, comes with great opportunity to align the rental housing stock with national thermal comfort goals. Provisions of the scheme, such as the technology innovation grant to facilitate adoption of innovative, sustainable, green and disaster-resilient technologies and building materials, must be linked to better thermal performance. The criterion for this grant is speedy, innovative and sustainable construction, which is quite open-ended and less binding. Here is where thermal comfort standards for different climate zones become crucial.

Currently, no housing scheme has parameters to ensure access to important infrastructure such as schools, healthcare facilities or public transport, says a 2021 CSE report, “Mass housing and liveability”. Even in slum rehabilitation projects, most times, beneficiaries are relocated to unsuitable peripheral locations that compromise liveability. This model results in creation of more slums and vacant housing at the periphery, CSE notes in another 2021 report titled “Towards affordable and sustainable rental housing”. Housing schemes must focus on in situ rehabilitation.

Alternatively, a balanced scorecard approach, in which sites with adequate access to infrastructure are prioritised, can help decision-makers ensure future housing stock has the crucial liveability parameters.

Further, affordable housing projects, and cities in general, are yet to reap the benefits of environmental services like nature-based decentralised wastewater treatment, in situ solid waste management and solar rooftop. This is despite incentives—for instance, under the PM Surya Ghar Muft Bijli Yojana, independent homeowners can avail a subsidy of Rs 30,000 per kW and group housing societies can avail Rs 18,000 per kW. Such benefits must be mandatory for affordable housing projects.

Heat management in cities 

The urban heat island effect has become widespread, affecting most cities and leading to increased heat exposure. This not only poses health risks to people, but could create a vicious cycle where air-conditioning becomes a quick fix for thermal comfort and ejects more heat into ambient environment.

The government has initiatives such as the India Cooling Action Plan, 2019; energy conservation building codes; National Mission for Sustainable Habitat 2.0; addendums to Urban and Regional Development Plan Formulation and Implementation (URDPFI) Guidelines, 2014; and Model Building Bye-Laws, 2016. However, heat management in cities has not seen comprehensive action so far. In an analysis of 37 heat action plans, Delhi-based think tank Centre for Policy Research reveals that focus is mainly on disaster preparedness and emergency response. Plans do not identify vulnerable groups and lack local bearing.

CSE also analysed four cities (Jaipur, Delhi, Pune and Kolkata) of various sizes and in different climate zones to understand how land surface temperatures (LSTs) may be affected by the height and density of buildings and roads, roof materials, natural green cover and water-bodies. The study revealed that cities can mitigate LSTs by as much as 10°C by increasing green spaces with thick canopy trees, reducing street exposure to the sun, enabling mutual shading and proper orientation of buildings and using materials that do not trap heat.

Cities must aim to increase their green space in line with the World Health Organization recommendations of at least 9 sq m per capita. URDPFI guidelines recommend a larger green space of 12-18 sq m per capita. Compact development with mid-rise buildings; heat-resilient streets that use water elements like fountains, swales and rain gardens; shading elements; reflective materials; and cool and green roofs can help enhance microclimate and improve thermal comfort to a great extent. All this must be captured in cities’ building by-laws.

Heat mitigation must also move beyond disaster response during a heatwave. Cities must assess vulnerability for prioritised and localised action, such as retrofits in certain areas. Global adaptation funds and current fiscal support to urban local bodies could be leveraged to enable these actions. Heat management needs to be institutionalised with city climate change cells, which are currently being set up, as a nodal agency.

Building potential 

Cities show a lot of potential to integrate solar energy in the urban built environment. The government, apart from increasing solar rooftop under the PM Suryoday scheme, can promote use of solar energy in electric vehicle charging stations, uncovered parking lots and other public spaces by leveraging state subsidies.

In construction, traditional technologies and materials like mud, thatch, bamboo, cob walls, adobe blocks, laterite blocks, wattle and daub are valued for climate responsiveness, since they protect from extreme heat or cold and improve thermal comfort; and are locally available and affordable. Rural communities, especially women, possess knowledge around their use.

This traditional wisdom must be documented, preserved and leveraged to enable thermal comfort in modern buildings. Some architects are already doing this through hybridisation, for example, using concrete columns and slabs for structural strength and mud-filled walls for thermal comfort. Such practices must be promoted and mainstreamed, especially in affordable housing.

C&D waste management

Construction and demolition (C&D) waste is India’s newest waste stream. Since the notification of C&D Waste Management Rules, 2016, India has set up nearly 31 recycling plants with 27 more underway, as per ongoing CSE research. However, cities are still working on their C&D waste ecosystem for smooth management and reuse.

While big cities have involved the private sector for setup and operations of the plant, small cities require fiscal support from the government. This is mainly because small urban local bodies are unable to ensure continuous waste feed for the plant, leaving private players hesitant to invest and implement projects. This calls for first setting up a collection system, then a plant.

The focus should not be just on recycling plants, but the entire ecosystem. This includes proper estimation of C&D waste generated, setting a convenient collection system and user charges, comprehensive by-laws that lay down duties of all stakeholders, ensuring reuse and uptake of recycled products, and creating awareness among the public.

This was first published in the 1-15 June, 2024 print edition of Down To Earth