Located on a busy stretch of Lloyds Road in Chennai, this commercial building nestles itself among a line of old residences, a few apartments and scrappy little shops and stores dotting this busy streetscape. Sited on the corner of the main road and a by lane, the building faces north towards the main road, east towards the by lane, west and south towards two old residences.
DESIGN INTENT Our main architectural intent apart from providing the clear floor plate for the office indoor, was to work on a passive method of providing a better indoor environment. Provide well distributed natural light, reduce the load on the air conditioning requirement and ensure the noise from the street below was kept out, to the best extent possible. This architectural intent, manifested itself in the form of a skin wall along the north, east and western sides of the building. Our first point of reference was a traditional brick jali screen wall. Stretcher courses, staggered at every alternate course creating the play of mass and void. We took this basic jali screen geometry and looked to tweak it to suit our requirement.
MATERIALS Our first material choice was to go with a flatter and longer brick (300Wx100Dx50H). The brick is hollow, with two cavities running along the length of the brick. Our reason for choosing this brick, is because of its lightweight nature, its air cavity which allows for lesser thermal heat gain and also because of its accurate dimensions and finished edges. The overall facade of the building is divided and broken down into clear panels of 600mm each with white aluminium mullions that define the edges. The infill skin space in between the mullions is divided into two distinct types. A panel for light and a performance jali screen panel.
LIGHT DISTRIBUTION The panels for light are distributed evenly across the floor plate, allowing for even natural light to be distributed through the floor space. This way no distinct bright spots and dark spots are created within the indoor space. The aluminium joinery which spans from beam bottom to floor level, allows the light to bounce and multiply, by reflecting off the white coloured floor and ceiling.
PERFORMANCE JALI SCREEN PANEL The performance jali screen panel in itself comprises of three distinct zones. The outer exposed brick jali screen wall of 100mm, a 50mm freely ventilated air cavity and a 200mm two side plastered concrete block work wall on the office indoor side. The ventilating nature of hollow brick core, the voids between the bricks and the ventilated air cavity between the brickwork and the block work all ensure that there is very little direct heat transferred from exterior face to the indoor environment. In fact the inner block work wall, almost never receives direct sunlight at any time of the day, as the jali screen edge soaks in the heat and vents it out through the various air cavities. This will greatly reduced the heat radiated within the indoor space and in turn will reduced the load on the air-conditioning systems. On the northern face of the building is the main road, which is fairly busy and can be quite noisy at times. Using the same panelised performance jali screen to the northern face, we are looking to reduce the level of penetration of this noise to a great extent. The pixelated facade with its air cavities, allows these noisy disturbances to attenuate and fade before they enter the office interior, thus allowing the indoor space to remain relatively disturbance free from unwanted noises.
ROOST RESISTANCE A standard problem faced with jali screen walls in urban situations, has been the roosting of pigeons and other similar birds. This has always been a problem, and has been tackled in many ways, like using nylon guide wire, metal spikes, low voltage electrical wires etc. Knowing this problem, was another critical reason in choosing the 50mm wide brick. The bricks are bonded by a cement based adhesive, not a conventional 10mm mortar joint, allowing us the ensure the voids are just fractionally larger than 50mm in height. 50mm being too small for prolific nesters like pigeons to roost, in a way made this jali screen wall roost-resistant.
MODULAR ZERO WASTAGE JALI SCREEN The construction of the brick jali screen, was to ensure that we have near zero percent wastage of material. The 300Lx150Bx50H brick is used in full as well as in site cut sizes of 230mm and 70mm, ensuring that there is no wastage. The adhesive used to bond the brick is also applied as a thin layer 3mm thick, with a small trowel. No removal of extra mortar, no spillage and no wastage. Each brick jali screen was further modularized into panels of 600mm width bound by aluminium mullions.