Majestic green building TNLA received a LEED Gold Certification from the Indian Green Building Council (IGBC) on 9th March, 2010.
Tamil Nadu is now home to the country’s largest government green building. This building is none other than the new Legislative Assembly for the State, built on Omanthoorar Estate in the State Capital of Chennai. The majestic green building that is the TNLA received a LEED (Leadership in Energy and Environmental Design) Gold Certification from the Indian Green Building Council (IGBC) on 9th March, 2010. LEED is an ecology-oriented internationally recognised building certification programme run in India, jointly by the Indian and the U.S. Green Building Councils.
The TNLA complex was awarded the aforementioned certification for adhering to guidelines of green buildings on site management, water efficiency and reduction in the use of water, energy efficiency, enhanced indoor air quality and conservation of materials and resources. The selection of the site for construction had already imparted 16 points to the building, said Deepa Sathiaram, director of En3 Sustainability Solutions.
The buildings within the assembly complex will use less water, consume less energy, preserve natural resources, generate less waste and provide a healthier environment for occupants as compared to conventional buildings. The entire site has been planned with provisions for open and landscaped spaces to promote bio-diversity.
The architecture of the exteriors of the buildings within the assembly complex is such that it minimises heat ingress. A large landscaped space has been maintained that keeps the surroundings cool by shading walkways, roads and car parks. The buildings have shaded windows, energy efficient glazing and screens that incorporate traditional ‘Kolam' designs.
A combination of a reflective roof and a green roof insulates the roof, filters water from various forms of precipitation and reduces heat islands that may form on the exteriors. Rain water harvesting with bore holes & RWH sumps is facilitated; recycled water is used for gardening. Being in a water-deficient city, an air cooling system was chosen for the complex instead of a water cooling system.
There is a multi-level car-park with a capacity to accomodate 600 to 800 cars at a time. This provision is likely to help reduce the heat island effect and control the microclimate. A guesthouse and a convention hall have been proposed. A sewage treatment plant which is equipped to treat 100 per cent of waste water from the complex and reuse it for landscaping has been installed.
Another key feature is the building's shape and exterior cladding. It takes the shape of a smooth arc which gleams obliquely against the linearity of the neighbourhood.
Detailed computer-based energy models to develop ventilation and energy conservation strategies were deployed. These helped make the necessary trade-offs to achieve a good level of energy efficiency.
Iconic Building Design Intent
The design of the assembly complex takes into account the culture and tradition of the State as well as the urban flavour of the city of Chennai. A high-rising dome mimics the structural features of Dravidian temple complexes in South India. The geometry of the complex’s structure is derived from the traditional round chakra or mandala motif & gopurams of the rathas of Mahabalipuram consisting of circles of various sizes inscribed in 36 isosceles triangles.
The internal plan features courtyard architecture with 4 round interior courts, which are functionally differentiated, creating public, semi-public and also secure internal areas. These 4 circular blocks are interconnected with each other. The spacious Citizens' Forum on the south side of the building is one of the interior courtyards and is created by the largest circle in the mandala. The three other round courtyards are of the Assembly Hall, the Legislative Assembly Chamber and the Convention Hall.
The first and the largest circular structure in the complex, the Public Plaza, has a motif that resembles a ‘Kolam’ design. Kolam is similar to the Rangoli but different in the manner in which it is created. In Kolam, dots are first placed and then connected with lines. There is a certain calculation involved, which is simple enough even for laypersons to understand and make. The Kolam was the design inspiration for architects of the TNLA.
In the Public Plaza, a Kolam engraved on natural sandstone covers 14,000 sq m of the floor space. Another Kolam which covers 10,000 sq m is engraved on the metal screen at the entrance of the complex.
From the very outset, the architectural team was keen on exploring the properties of reflected light and the potential of creating a translucent or opaque cladding solution that would allow light to pass through and provide diffused interior lighting during the daytime. Glass was the architects’ best bet to achieve this end; glass panels with aluminium cladding have been installed.
Saint-Gobain Glass India is among the providers of “Green Solutions” for this facility. Its premium product SGG Planitherm, an advanced thermal insulation glass that minimises energy consumption by keeping out unwanted heat and reducing cooling costs, has contributed greatly towards enhancing the energy-efficiency of the buildings within the assembly complex.
This Glass is manufactured by coating clear float glass with metallic oxides through a process of magnetically enhanced cathodic sputtering under vacuum conditions. It has a neutral appearance due to very low reflection. SGG Planitherm has high light transmission properties with excellent colour rendering, thus enabling most parts of a building to receive natural daylight – A critical factor that determines the ‘green quotient’ of a building.