The Background:
The school building for one of the leading educational institutions of Chennai, Vidya Mandir, is set on a 2 acre site in the periphery of Chennai. It is a part of a 26 acre property of a large Information Technology company that needed to build a High school in its premises for the children of its employees. The site faces West and is adjoining a mandatory open space reservation of over 2 acres to the South that could be used as a play area for the school. The school has been envisioned as a non air-conditioned school that should be energy efficient, cost efficient and easy to maintain over the years. It is to house 1100 students and there needs to be enough free space for them to move around, especially at school arrival or leaving times. The access to play areas and open spaces should always be easy, convenient and accessible to the differently-abled as well.
The Design:
The design strategy focuses on a building that would respond to the hot and humid climate of Chennai. While the weather is hot and humid almost all through the year, there is a cool sea breeze that flows across the city from the South and South-East directions. The design approach has been simple - to harness this breeze into the building by using deep verandas and covered walkways, while shading the building from the direct sun falling on the external walls of the building.
The school is conceived as a three floor building and has been designed with a naturally ventilated, single-loaded classroom building ribbon that runs parallel to the site boundaries. The building includes a large courtyard in the centre and is punctuated by deep verandas of varying volumes on all the sides that act as wind tunnels. The classrooms are predominantly in the upper two levels with the lower levels housing the administration offices, a few laboratories and ancillary rooms and some multi-use veranda spaces. The entrance to the school is on the west. A large tree-lined concourse along the front of the school allows for a large number of students to gather either at the start of school or at school leaving time. This space leads to a covered assembly area which in turn opens into the central courtyard, revealing a free flowing organisation of partly covered, fully covered and open to sky spaces. A straight flight of stairs from the concourse takes students straight to the classroom levels, thereby distributing the students movement to different levels. The courtyard acts as a central congregational square of about 750 sqm, which acts as the "heart" and 'lung" for the entire school. Following a dip in the profile of the land towards the East, this courtyard leads one to a large, covered and high-volume multi-purpose space that again opens out to the play areas at the rear.
While allowing the breeze in, it is important to keep the sun out. The sun-path has been carefully studied with particular focus for during the working hours of the school between 8:00 am and 3:30 pm. A glass fibre reinforced concrete (GFRC), perforated screen was designed as a building envelope that protected the external wall from the sun and glare. As a material, GFRC is locally made, light-weight, long-lasting and easy to maintain as well. The perforations in the external skin have been articulated to beat different sun-angles on the four sides of the building. As a result, the windows behind the screens are kept open at all times bringing in natural light and breeze into the classrooms while keeping out the glare and direct heat of the sun. The terrace of the building has been thermally treated with the use of white coated high solar reflective index (SRI) tiles that considerably reduce the heat gained from the roof. The six trees planted in the central courtyard also act as sun-shaders and are located at appropriate distances based on the sun angles to provide shade for the children during the school hours. Over a hundred young trees have been planted around the school campus and in a few years time, the school, its courtyard and the play areas around would be under the shade of the trees.
The modular classrooms accommodate 36 students and are located on a singly loaded corridor 2.5m wide that overlook the central courtyard. Sixty percent of the external walls of the classrooms have windows. Suspended on a concrete framework, the wall is covered by a veil formed by the perforated GFRC screen that lets in a lot of glare-free light and air. Fixed stone-shelved storages form the corridor side partition of the classrooms and are open at the top to facilitate cross ventilation. The science , mathematics and computer laboratories are located in a central block that is easily connected to the classroom wings. These rooms are accessed by sky-lit corridors that are ventilated by a clearstory raised roof.
It was a pre-requisite that the school be barrier free and visually well connected. Hence the corridors are column free and inclined concrete parapets that seem to float give a clear view right through the school. Because of this openness, the corridors and the verandahs along with the central courtyard harness the ambient prevalent breeze. There is an easy connect to the open spaces from the covered verandah spaces for student activities and 'outside of classroom' instruction.
The Vidya Mandir school building thus fulfils the mandate set by the design brief in being a cost efficient building with low maintenance, built using local materials and skill and also being energy efficient due to its climate friendly design approach with an open and free flowing spatial organisation.