Why India needs to get aggressive about passive cooling 

In part 2 of its series on cooling in India, CarbonCopy explores how income disparity, inadequate data and lack of awareness about building codes are major obstacles to achieving India Action Cooling Plan’s passive cooling strategy

In 2022, after two phases of the PM’s scheme to build affordable housing (Pradhan Mantri Awas Yojana-PMAY) were over, the government released recommendations for passive and low-energy cooling in which it acknowledged: “current design and construction practices are not streamlined for affordable housing and, therefore, this report recommends passive strategies to reduce heat gain from the building envelope [shell of the building] and low-energy cooling technologies to enhance thermal comfort, considering affordable housing and cost-related aspects.” 

The study pointed out that in the absence of additional policy interventions, room air conditioner (RAC) penetration will reach 239 million units by 2030—although this study has calculated a more realistic figure of 18 million units by 2031, which is still considerable. The exponential growth in the RAC stock will also give rise to the heat island effect, which will impact the poor in the affordable housing sector. 

We read in Part I, that means of active cooling, which include ACs, coolers, fans and above all expensive fuel and electricity can leave millions out of the pale of “thermal comfort” that the India Cooling Action Plan (ICAP) promises. However, the plan also recommends means of passive cooling, which cannot be bought from the market, but requires a mass implementation of India’s many progressive building norms that can keep the built and unbuilt environment cool without using mechanical cooling. So can the national building norms be “deconstructed” for the local builders and state bodies to be adopted at scale? How soon?

Passive cooling vs massive shortage of houses

The government report on passive cooling strategies points out that in India’s affordable housing sector, as of the 2011 Census, 377 million people (31%) reside in urban areas, with an expected increase of over 200 million by 2031. The government said, of the total shortage of 18.78 million housing units in Indian cities, 96% is required by Economically Weaker Sections and Low Income Group households. The report warned that the affordable housing shortage is expected to reach 44-48 million dwelling units by 2022. As per the same report, a majority of the shortage (14.99 million households) are living in congested houses, requiring new houses to be built. The report found that Uttar Pradesh has the highest shortage (3.07 million units), followed by Maharashtra with 1.94 million and West Bengal with 1.33 million.

Pradhan Mantri Awas Yojana-PMAY: ‘No focus on housing livability’

Government told Parliament on August 1, 2024, that “based on the project proposals submitted by States/ UTs, as on July 22, 2024, 118.64 lakh houses have been sanctioned under PMAY-U, of which 114.33 lakh houses have been grounded for construction; of which 85.04 lakh have been completed/delivered to beneficiaries. The sanctioned houses involve Central assistance of ₹2 lakh crore (approx.) against which ₹1.64 lakh crore has been released so far. The scheme period, which was earlier up to March 2022, has been extended upto December 2024.”

According to the passive cooling strategies report, to cater to housing needs, the Centre launched the Housing for All scheme in 2015. The report adds that the focus of PMAY-Urban is to build housing units quickly, with income, built space provisions and the cost of the dwelling unit as the determining criteria of affordable housing. But more importantly, the report points out that “there is limited or no focus on qualitative aspects that determine housing livability and occupant productivity.”

The passive cooling strategies report offers highest-impact measures such as orientation of the building, windows shading, glazing type, cross and night flush ventilation, wall materials/ techniques, envelope Insulation, roof materials etc. for different climate scenarios such as hot & dry climates, warm-humid climates and composite climatic conditions. The report recommended autoclaved aerated concrete (AAC) and hollow blocks as suitable in all climates. Other materials like clay bricks, cellular concrete, and fly ash are ideal in most climates.

Can the poor afford the ‘affordable housing’ recommendations?

According to Delhi-based architect Sanjay Sen Choudhury, the current building codes and strategies for affordable housing are energy efficient and progressive. But building a house by the book is expensive for the majority of the population. Sen said: “To integrate the code [including the passive cooling features] into the design of a home, we require architects who need to be paid for their services, obviously, but most people can’t afford them and there are no incentives to hire their services or follow the code either.”

Sen says, “Realistically speaking, given the density of space, it is not even possible for architects to design naturally ventilated homes that are not dependent on ACs, anyway. For that, homes require open space around them on at least two sides for the right amount of airflow. It requires architectural features to minimise solar radiation through windows, right building materials to minimise heating, these materials are too expensive for even the middle class let alone the poor who bear the brunt of heat-related fatalities.”

Homes stacked like cartons in the warehouse

Drawing crucial distinctions between the way the rich and the poor use resources, Sen says, “It’s for everyone to see. The density of homes in urban areas is such that in many cases, it is hard to differentiate between a slum and urban housing. For which, ACs and coolers are the best options for survival. The middle class and the poor are blamed for guzzling energy through mechanical cooling. But architecturally, that’s not true. There is very little surface left for solar radiation to fall upon the walls on most of the urban homes in cities with common walls between the homes on three sides, stacked like cardboard cartons in warehouses, in most urban areas where the poor or the middle class live. Compare it to the leafy avenues of bungalows with open lawns on all four sides. It is them who use the maximum number of ACs on all exposed sides in a room one could use depending upon their (much larger) sizes.” 

This lack of space for cooling for the poor is an important differentiating factor that has been missed by policymakers. 

Lack of vulnerability mapping

​​The cooling action plan also lacks vulnerability mapping data based on the thermal needs of those residing in vulnerable regions. More than 100 cities have a heat action plan, but 97% of the plans do not undertake risk and vulnerability assessment.  

The Delhi heat action plan talks about heat deaths and how the poor “struggle to maintain thermal comfort due to the high costs of cooling.” The ICAP acknowledges that cooling should be made “accessible for all” but does not address the high costs of cooling. Many people are still living without electricity because they cannot afford high costs of electricity connection, let alone buy a fan or AC. Consider the anomalies between states. According to India Residential Energy Survey (IRES) 2020, 2.4% of Indian households still remain unelectrified. Most of them were concentrated in rural Uttar Pradesh, Madhya Pradesh, Rajasthan, Haryana, and Bihar. The IRES survey found that a majority of them could not afford grid-connection. The Saubhagya scheme offers a free connection, but some households are not able to access it, or were deterred by the recurring monthly expenditure of paying electricity charges, the IRES report said. The report stated that some households do not have electricity because they lack grid supply in the neighbourhood, or they are refused connection due to inadequate documents.

According to a CEEW study, government data GARV2 dashboard shows that 37% of households in Odisha are unelectrified, even as over 98% of villages in the state have been electrified.

Building codes waiting to be noticed

The ICAP recommends implementation of building codes to achieve cooling targets. The Energy Conservation Building Code (ECBC) (Residential) itself acknowledges that “although the temperatures are high during a major part of the year requiring mechanical space cooling, consideration of heat gain is often not given sufficient importance during residential building design.”

Just as ECBC rues lack of implementation, a study by WRI found that a majority of the key state agencies are not even aware of ICAP, without which plan implementation is not impossible. The ICAP recommends green buildings based on Energy Conservation Building Code 2017, but the code that was launched in 2007 and revised in 2017 “to incorporate advanced technologies” is applicable only to commercial buildings.

Speaking to Carboncopy, Anumita Roychowdhury of the Centre for Science and Environment (CSE) said even as energy efficiency building codes have evolved, there are gaps between the policy and policy enabling mechanism for scalable implementation, which will require local interventions such as modifying local building bylaws. 

“We require a huge outrage which is directly linked with the mandate of various laws pushing for thermal comfort. These laws need to be demystified for urban planners, local bodies, architects, and the builders’ community so that the design required for thermal comfort gets absorbed while designing massive housing projects that are not supposed to have air conditioners. But at the ground level what we see is this cookie cutter approach to building and designing mass projects with no evaluation of how good they are prepared for day and night temperature gain, no attention paid to orientation of the building or how the wind flows through the rooms all these parameters get ignored.”

Roy pointed out that even as scientists are classifying building material according to a heat gain index, the market is not responsive. The new material to build has moved away from brick and mortar to prefabricated walls, which are heat trappers. “On the one hand, the policy has been progressive and aims to reduce mechanical cooling; earlier the focus was on energy efficiency but now also includes thermal comfort. There is a strategic shift with respect to cooling as ICAP acknowledges thermal comfort, but to operationalise it one has to join a lot of dots which is not happening, it’s happening only in specific projects, but it’s not adopted in mass construction.”

The absence of clear benchmarks and clear definitions of concepts such as “thermal comfort” can upset the country’s energy budget. The time to get to the grain of the issues is now, she said.

This is Part 2, read Part 1 here.

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Moonis Ijlal

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