In the interim Budget 2024, Finance Minister Nirmala Sitharaman announced the construction of two crore additional houses over the next five years under the Pradhan Mantri Awas Yojana Gramin (PMAY-G) and the introduction of a new housing scheme for the middle class. This is a commendable step towards realising the goals of the ambitious ‘Housing for All’ initiative and builds on the success of the PMAY scheme, which has facilitated the construction of nearly three crore rural and 80 lakh urban affordable houses since 2015.
The announcement also prompts us to critically think about the potential trade-offs with quality of life and environmental concerns as a result of the rapid expansion of the housing sector. This is evident in the case of affordable housing, where the emphasis is on mass production, prioritising speed, cost, and ease of construction over factors such as thermal comfort and the implementation of low-carbon infrastructure.
Modern technologies in affordable housing
Within the framework of the PMAY mission, Light House Projects (LHPs) are underway as part of the Global Housing Technology Challenge (GHTC), spanning six sites across six States. These LHPs leverage modern technology and innovative processes so as to reduce construction time and build more resilient and affordable houses for the underprivileged. Additionally, there are ongoing efforts to utilise alternative construction technologies such as Mivan. This technology utilises advanced aluminium formwork, which is recyclable and reusable, to cast and construct various building elements. This approach surpasses traditional construction methods in terms of speed and quality and has a relatively lower environmental impact due to reduced wastage in the construction phase.
Though construction technologies such as Mivan offer higher efficiency and reduce the overall duration and cost of the project, they present a conundrum. The extensive use of cement and steel without proper insulation results in increased heat gain from the building envelope, causing thermal distress. Consequently, occupants resort to increased use of cooling appliances such as air conditioners. This reliance on cooling appliances triggers a surge in electricity consumption, thereby contributing to elevated greenhouse gas (GHG) emissions. Further, the predominant use of lower efficiency appliances (despite the availability of high efficiency appliances) owing to lower purchase costs leads to higher electricity consumption and resultant greenhouse gas emissions. This underscores a critical paradox, wherein a technology deemed to offer a low-carbon alternative inadvertently contributes to elevated emissions during the operational stage.
Prioritising thermal comfort
The escalating heat stress worldwide is anticipated to affect various population segments, leading to a substantial increase in the demand for cooling. However, the impact of this rising demand will be pronounced among communities belonging to the low-income strata with limited access to cooling amenities. Therefore, to make vulnerable communities resilient to heat stress, it is imperative that building houses go beyond provisioning basic amenities by integrating passive design strategies for thermal comfort. Such steps would help align the ‘Housing for All’ vision with broader environmental and climate goals.
The pathway to achieving a harmonious balance among multiple goals lies in the obligatory implementation of guidelines embedded within building codes, as demonstrated by initiatives such as Eco Niwas Samhita. This framework directs attention towards refining building envelope characteristics pertaining to specific climate zones, thereby facilitating a thermally comfortable environment within built spaces. The Smart Ghar III project in Rajkot, an affordable housing initiative under the PMAY Untenable Slum Redevelopment project, serves as a prime example of achieving indoor thermal comfort through passive design implementation. As various construction technologies are being tested for LHPs, there is no better opportune time than now to incorporate detailed passive design aspects in building design mandating the adoption of codes and guidelines.
However, the challenge lies in their implementation because of the multi-stakeholder nature of the building value chain. This involves architects, engineers, contractors, material suppliers, and end-users, each with their own priorities, constraints and levels of awareness regarding sustainable practices. One major hurdle in promoting the adoption of passive designs is the lack of tangible benefits perceived by the end-users owing to a lack of awareness. While passive designs offer long-term benefits such as reduced energy bills and improved comfort, these advantages are not always immediately apparent to homeowners.
Therefore, an ecosystem change is needed across the entire value chain to encourage the adoption and rightful implementation of the codes. This requires raising awareness and fostering collaboration among stakeholders and incentivising developers to prioritise passive designs.
Buildings for tomorrow
Considering the growing significance of the building sector and its contribution to GHG emissions, the need to address the environmental impact of construction activities is imperative. With an increasing number of building stocks on the horizon, it is important to analyse the trade-offs between embodied and operational emissions. By weaving environmental consciousness into the fabric of housing initiatives, we can ensure that the homes we build not only shelter individuals but are also robust structures that make residents resilient to a warming climate. This approach ensures that our collective housing aspirations contribute positively to the environment and serve as models for a sustainable and inclusive future.
Sarah Khan works in the area of climate mitigation at the Center for Study of Science, Technology and Policy (CSTEP), a Bengaluru-based think tank. Sweta Bhushan works in the area of climate mitigation at the Center for Study of Science, Technology and Policy (CSTEP), a Bengaluru-based think tank
