The construction industry in India is booming with over 60 per cent of the building stock still to be constructed. There is no question that India should build green. For those who think otherwise, let’s look at some environmental impacts of the sector. In India, buildings are responsible for 40 per cent of the energy use, 30 per cent of raw material use, 20 per-cent of land use. They also contribute to 40 per cent of carbon emissions, 30 per cent of solid waste generation and 20 per cent of water effluents.
An enormous demand of natural resources is generated by building construction also the waste produced by demolition and retrofitting is enormous. So unlike the rest of the developed world, the challenge is to build green. Thus, the question is addressing what is green and what it truly means in India context.
Across the country, various ideas of green building have emerged with multiple small or big constructions advertised as greenest of green. India is now the second largest market for green buildings. The trend is entirely market-driven and is achieved with very little government support. Various agencies have grown up to stimulate the performance and rate, award stars to individual buildings.
The sophisticated technology-based solutions require a high initial investment that only few can afford. On the other end affordable, low-cost technologies, such as mud architecture, are already available but are not widely accepted by the urban population. Only the brave would discuss the post-commission performance of a “high-tech” green building. An elite club of architects, builders, manufacturers and auditors is created by the rise of this green construction in India. It is strange that no one wants to question the approach of first building wrong (failing to incorporate the critical dimension of social and cultural sustainability in the Indian context) and then fitting green features as an afterthought.
The glazed buildings of Gurgaon, Bangalore speak for themselves. Though there is a considerable variation in the climate of these two cities, there is little change in the use of glass. The Energy Conservation Building Code (ECBC) established by the Indian Bureau of Energy Efficiency (BEE) was set for determining energy efficiency standards for design and construction of buildings. To the surprise of many, the ECBC has prescribed wall-window ratio and specifies that the building envelope can be covered with glass by 60 per-cent. The above statement means that a building a building can be green if it is covered with glass. ECBC prescribes the use of high-performance glass that is solar reflective and has high insulation and energy efficiency. The buildings wrapped around the glass are now certified as green, and the green building business is thriving.
In India today the rapidly growing middle class is resulting in the construction of various derivations of globalisation. The architecture because of the rise of impatient capitalism is showing complete detachment from social and cultural context. Material usage does not comply with local resources available but tend towards technologies that meet international standards. Most large-scale buildings are portraying a new landscape of global derivation while forcefully compiling to the environmental impact assessment (EIA). The EIA rules were introduced under Environment Protection Act, 1986 which were meant for large construction projects having a built-up area more than 20,000 sq. m.
There is a need for additional policy measures, strict regulatory bodies and creating incentives for passive architectural approaches and alternative material use to increase the thermal comfort of buildings. This can open opportunities for innovation in passive architecture to minimise the use of mechanical cooling and save on energy consumption. To design a building in such a way that it optimises orientation, daylight and ventilation also reducing overheating through exposed glass and surfaces. The use of wide variety of shading devices, using a range of cooling, ventilation and insulating techniques can cut energy demands by a considerable margin.
Architects have used various innovative design features to reduce solar heat gain lke cavity walls, filler slabs, double roofs, etc. Use of materials that are made on site like compressed stabalized mud blocks (CSMB) reduce the emboide energy, also they are made from the soil which is procuried from the site after excavation. Other materials include autoclaved aerated concrete blocks , hollow bricks or other building materials with inherit higer “R-value” that can increae building insulation. Rammed earth, bambaoo counstrucion practises require incentives from regulatory bodies as they cannot meet the insulation values need for fully air-conditioned buildings. Green building regulations need to consider climate sensitivities and then govern the choice of material and design.
Interestingly we as architects can incorporate waste in our buildings as a substitute to landfills. If we bury the waste under the buildings on low water table areas, the waste will not be exposed to sun and rain and will work as damp roofing. The foundation in a weak soil requires an economical design. The old processed concrete from the demolished building can be used to make plum concrete. Well foundations utilizing this plum concrete can support grade beams on which the building can be rested. This alternative to the conventional foundation serves not only as an elegant solution to a specific problem but also helps reduce the waste generated from the site going and defacing someone else backyard.
Afte a building is constructed, it lies on land which is no longer productive. Thus foundation, plinth, infills, sunken floors, etc. are ideal for holding waste. Also, new buildings can be seen as a sink for debris and waste of demolished buildings. The various materials obtained from old buildings reused in foundations, walls, windows or made into an art piece.
Incorporating water management technologies in design like cutting on water use and wastewater discharge at an individual or collective levels is at the heart of water sustainability. Groundwater management can be done by giving special considerations to replenish aquifers and limiting digging of new borewells. Instead incorporating rainwater harvesting, use of recharge wells, wastewater (grey and black water ) re-use after treatment for a non-portable purpose. Water from toilets or black water too can be treated by addition of baffle reactor. Acquisitions of such systems not only reduces wastewater generation but also contributes towards providing water security to our cities.
India should not copy the west in designing its codes but rather to incorporate the critical dimension of social and cultural sustainability in the Indian context. It is time to bring back the traditional building sense of localising buildings. Many professionals are building a better future by creating affordable, sustainable buildings for a better future.
For understanding green, we have to understand what sustainability is all about. Sustainability is not a hi-tech building with fancy features it is an amalgamation of smart design and thoughtfulness, contextual understanding of the microclimate where a building will be built. There are vernacular buildings which are greener than the GRIHA platinum buildings. Instead of creating a cyborg It will be better to make a tree which is self-sustainable and caters to the needs of the surroundings too.