According to the Global Air Pollution Database compiled by the World Health Organization (WHO), out of the fifteen most polluted cities of the world, fourteen are Indian cities. The report also states nine out of ten people in the world breathe polluted air.

Urban centres are primary sources of emission of greenhouse gases (GHGs) as they concentrate on populations, economic activities and concrete environments. Moreover, growing urbanization is causing an increase in migration, number of slums, load on infrastructure, number of vehicles, use of non-renewable sources and other similar problems. What we need under these circumstances is more buildings like the Indira Paryavaran Bhawan- India's first zero-carbon building (or net zero energy use office building).

What is a zero-carbon building?

According to the Australian Sustainable Built Environment Council (ASBEC), zero-carbon buildings are those having no net annual emissions from direct fuel combustion and electricity use from building operations.

Low carbon construction action plan

To achieve a zero-carbon status, buildings require reduced energy consumption while generating enough on-site energy to meet the building's energy demands.

Reducing the amount of energy used and increasing the efficiency of homes is the most cost-effective way of achieving a zero-carbon status. The most common ways of doing this are installing rooftop solar and photovoltaic systems (PV) which convert sunlight into electricity.

There are a few everyday steps one could take to make their home sustainable in its daily functioning:

• Open windows in the mornings and evenings to increase ventilation during summer
• Use individual air-conditioning (AC) systems instead of central air-conditioning systems
• Use energy-efficient appliances
• Reduce electrical appliance usage- turn off lights, switch off appliances and equipment at the plug when not in use
• Instead of depositing food and garden waste into the landfill, try using that as compost
• Try to grow some organic vegetables and food in balconies, gardens or patios
• Save water and energy used in heating it by taking shorter showers and by washing clothes in cold water
• Install curtains and blinds to reduce the need for additional cooling
• Use double-glazed windows to block the heat and reduce the pressure on AC systems

To reiterate, zero-carbon buildings produce an equal amount of energy through renewable sources as they consume annually. Indira Paryavaran Bhawan is one such building as it houses a rooftop solar PV system through which it aims to generate 1.4 million kWh of energy annually. The building also uses less water than a conventional building of the same size would. It is oriented east-west for maximum cross-ventilation and uses geothermal cooling in its AC and heating systems.

Among other initiatives towards constructing energy efficient and zero-carbon buildings, India formulated the Integrated Energy Policy of 2006 which discusses ways to promote energy efficiency in all sectors and focusses on mass transport, renewable materials and research and development of clean-energy related technologies.

Energy Conservation Building Code was also launched in May 2007 to promote and offer recommendations and mandates for construction of energy-efficient buildings.