The new Legislative Assembly building on Omanthoorar Estate on Tuesday received LEED (Leadership in Energy and Environmental Design) Gold Certification from the Indian Green Building Council (IGBC).

LEED is an ecology-oriented internationally recognised building certification programme run in India jointly by the Indian and the U.S. Green Building Councils.

According to the certificate, the building has become India's largest governmental green building. Chief Minister M. Karunanidhi visited the building on Tuesday and congratulated the officials on the achievement of the green rating.

The project is the single largest green initiative of a public facility of this scale and importance in the country.

The building would use less water, consume less energy, preserve natural resources, generate less waste and provide healthier space for occupants, as compared to a conventional building.

The building has set the tone for future developments in this region, said Deepa Sathiaram, Director of En3 Sustainability Solutions, the consultant of the project.

The building was awarded the certification for adhering to guidelines of green buildings on site management, water efficiency and water use reduction, energy efficiency, enhanced indoor environmental quality and conservation of materials and resources.

The entire site has been well-planned with lot of open and landscaped space to promote bio-diversity and has made provisions to promote alternative transportation. The exterior design has been planned to reduce heat ingress into the building by maintaining landscaped space to cool the exterior and by shading the walkways, roads and car parks.

A combination of a reflective roof and a green roof insulates the roof, filters stormwater and further reduces heat islands on the building exterior.

Another key aspect is the building's shape and exterior cladding. It is designed as a smooth arc which gleams obliquely against the linearity of the neighbourhood.

The exterior of the building has shaded windows, energy efficient glazing and a screen that incorporates traditional ‘kolam' designs.

The facade achieves a thermal break between the exterior and interior, facilitating more efficient cooling and reduced direct heat radiation, Ms. Sathiaram said.

Detailed computer-based energy models of the building to develop ventilation and energy strategies were deployed to make the necessary trade-offs to achieve a good level of energy performance.