Policy Briefs

Building Sustainable Homes: Strengthening Sustainability at Community Level

Housing is a basic human requirement for better lives, and building houses that are livable and affordable is a key aspiration for governments across the world. According to UN Habitat, two-fifths of the global population or 3 billion people will need adequate housing by 2030. That means that 96,000 new housing units will be in demand every day¹ . It calls for housing to be a top-most priority for governments.

At the same time, this construction imperative must be developed with sustainability at its heart, in order to align with the needs of climate action and environmental protection and conservation. Incorporating green practices into housing units will also raise community awareness and participation in sustainability, ensuring success of efficient power, water and sanitation facilities. Making buildings green is a significant challenge that policymakers face today.

The International Taskforce of Green Building Councils² has delineated various best practices that inform the green building requirements. First, habitability and comfort parameters should boost mental and physical well-being of residents, including adequate and good quality air, light, water sanitation, thermal and visual comfort. The outdoor environment must provide access to nature and ensure walkability.

Second, to strengthen community and connectivity, citizens should be involved in planning and designing of projects. The projects must build-in accessible transport so that residents have easy mobility to places of work, healthcare and education facilities, public services, and public areas.

Third, resilience and adaptation to climate change should be a part of housing developments. Adaptable, durable and easily maintained housing with ease of retrofit and reuse can enhance longevity of housing. Nature based solutions can also be deployed by enhancing natural capital and supporting ecological health.

Fourth, housing should look at carbon emission reduction and zero operational carbon levels. Use of clean energy, energy efficiency, efficient use of water and waste management should be included in the building design to last through the life cycle.

Fifth, affordability and minimal maintenance costs are a priority to increase disposable income for low-income residents. Sourcing locally to reduce building costs is also recommended so that local economies can benefit.

Source: World Green Building Council³

The first step towards green homes is sustainable design. Residential construction and site development generally can be expected to negatively impact the site ecology, natural vegetation, stormwater runoff patterns, perviousness, and fauna at the site. Therefore, site selection must consider environmental impact, identifying major ecological features such as topography, trees and vegetation, wildlife and site history.

Projects must be designed⁴ to implement post occupancy strategies such as rainwater harvesting pits, storm water drains and sedimentation control. Vegetation should be retained as far as possible to mitigate soil erosion. This can be done before and during the construction, with fertile topsoil stockpiled in advance for later use. Vegetation can also be included on the built structure to develop adequate green space, for example on roof or podium surfaces or vertical surfaces. At least 30% of the site area would need to be allocated for green plants.

How can built housing reduce the impact of heat islands created by the construction on micro-climate and local biodiversity? In the non-roof areas such as footpaths, roads, uncovered parking and so on, shade from tree cover, open grid pavers or grass pavers and hardscape materials of desired grade can be used to reduce heat impact of the built areas. For the exposed roof areas, materials with a high solar reflective index can be used, including steeper slopes. White or light colored tiles, reflective coatings and other high reflective materials are good options towards green buildings.

Passive architecture steps help in designing an efficient building envelope, reducing energy consumption and mitigating negative environmental impact. Exterior openings with high projection factor, skylights, daylight illumination and passive cooling and heating technologies such as wind towers and earth tunnels must be part of project design.

A study can be done of the Indian Green Building Council (IGBC), a certification body and a founding member of World Green Building Council. IGBC has a pipeline of 14,510 projects in India with a green footprint of over 12.3 billion square feet, of which over 5,800 projects are certified and fully operational. IGBC has developed four Green Residential ratings for green homes, green affordable housing, green residential societies and NEST for self-developed houses.

Within these, the Green Affordable Housing rating, tailored to Indian conditions, aims to certify projects that are appropriate, affordable and environment conscious. The rating assesses central indicators of affordable housing such as standard and quality, availability of basic amenities, easy access to services, jobs and community facilities, water and energy efficiency, and cost of maintenance and operations. Thus, it addresses green features related to sustainable site, water conservation, energy conservation, materials conservation, indoor environmental quality, and innovation and design process.

Taken to a national level, such a certification can provide cumulative benefits to the country in terms of reduction in overall energy and water consumption, better health and hygiene, better ventilation and natural lighting, and savings in transit of people. The rating is applicable for the Indian affordable housing project of Pradhan Mantri Awas Yojana (Prime Minister’s Housing Project or PMAY).

A range of matters would need to be taken up by governments which wish to accelerate green housing in their countries, particularly in less developed countries. Apart from an assessment and ratings system, governments can consider putting in place the ecosystem for manufacturing and certification of green construction materials. Encouraging such manufacturing at the local level will not only boost green affordable housing construction, but will also help to create jobs and boost local SMEs and local economies.

The sites selected for community housing programs must be well-considered with respect to environmental impact and sedimentation, and must also align with existing or future transportation facilities. Parks, trees and accessibility to nature can be part of the project to maintain healthy and hygienic living.

In addition, governments need to institute norms and standards for energy efficiency, water efficiency, waste management and transportation facilities for low-cost housing projects. Such projects can be monitored for ensuring that norms are met.

Given the high volume of low-cost housing likely to come up across the world in the next few years, green housing will remain a priority consideration for governments.

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