This project (had) many firsts for me: my first government sector project, my first public building and my first attempt at designing a sustainable building.
This project is located in Pimpri- Chinchwad, a twin city of Pune. A city with a huge concentration of industries and a population of about 23 lakhs. The Pimpri Chinchwad new Town Development Authority guides and directs the development of a sizeable part of this city.
The new administrative building for PCNTDA had of course to be iconic, however, I felt that it ought to make a statement, though in a meaningful sense. I pushed for the building to be designed 'green'.
This was in 2008, when awareness in government departments about green buildings was scanty, if at all.
Pune, though classified as part of the humungous ‘warm and humid zone’ in the ECBC climate map, has a rather moderate climate, except for the 2.5-3 months of summer.
A further blessing is that as the temperatures rise, so does the wind, as this windrose diagram illustrates. This westerly wind is actually cool sea breeze from the Arabian sea that travels about 100 km inland, having climbed up the steep western ghats, and losing quite a bit of its moisture enroute.
We all know that when it is really warm, air movement can provide relief and comfort.
The building form that we came up with was a resultant of the functional requirements juxtaposed with solar passive principles. This involved orienting and locating the various (functional components) with respect to the sun for thermal comfort, enhancing this by enabling cross ventilation and maximizing daylight without ending up with heat gain.
Pune being located at approximately 18.5 degrees north latitude, north is the most appropriate orientation for daylight.
So we have these two narrow, about 14 mtr wide northward, (actually NNE) facing earth-coloured blocks, that rise up starkly to nearly 30 metres from the ground, staggered so that daylight is achieved and views are unhindered. The blocks are connected by an open, curved connecting bridge at each floor level.
Each block is composed of an L shaped module stacked vertically, a module that was well suited to accommodate the nearly typical functional structure of the various departments in PCNTDA. The triangular spaces in plan house lifts, staircase blocks and toilets.
The narrow easterly and westerly facades are scooped out in the wind flow direction, the resulting form almost inviting the wind to flow in. The fenestration is more of a textural treatment, with shading devices designed appropriate to each orientation. The east and west walls have large openings, shaded with horizontal louvers to block direct radiation, but to allow for free flow of wind across. Many small but significant features are incorporated such as perforations in the parapet to carry away hot air that stagnates at the surface of the roof, or stack ventilation for the toilet blocks, that prevents odour spreading to the rest of the building.
Evaporative cooling is achieved for the canteen area located above the parking block, by means of westerly wind blowing over fountains in a waterbody on the terrace garden.
The energy and comfort simulations were carried out by TERI, and to my delight, they predicted that just using ceiling fans, the building would have unsatisfactory comfort conditions for only 4% of the annual habitable hours. This has been (amply demonstrated), now that the building is in use for nearly 3 years now.
Since there is very little air-conditioning, the energy footprint is so low that the entire building of nearly 1.4 lakh sqft is run entirely on an online 100 Kw Solar PV system.
Green measures were employed during the construction process too, my two favourite ones are: that we were successful in channelizing all run-off into a sedimentation tank, which became a bird-sanctuary of sorts, and the water trench that was created at the entrance, to wet the wheels of the construction vehicles, so that they wouldn’t kick up too much dust in and around the site.
This is a project that for the first time gave me enough freedom and space to explore the use of geometry to not only create a distinctive form and massing, but to succeed in fulfilling functional requirements as well as climate- responsive design goals. My conviction has only grown stronger that naturally ventilated, low- energy buildings can work just fine in a climate like Pune's.
