Sarbjit Singh Bahga –
It is widely known today that Sustainable Architecture refers to the creation of a building, structure or composite built-environment through a process that is environmentally responsible and resource-efficient throughout a building’s life-cycle: from site selection to design, construction, operation, maintenance, renovation and demolition. Sustainable buildings are aimed to reduce the overall impact of the built-environment on human health and natural environment by:
- Saving energy through passive and active means.
- Efficiently using water and managing storm water / recycled water.
- Protecting the occupants’ health by improving indoor air quality, and enhancing productivity.
- Reducing waste, construction materials, pollution and environmental degradation.
- Improving the micro-climate by landscaping the surroundings.
In India we have a long tradition of sustainability. It is deeply rooted in our culture. The holistic approach was the mindset of our forefathers. The Indian way of life is aparigraha (minimum possession), conservation (minimum consumption), and recycling (minimum waste). These three attributes are the guiding principles for sustaining buildings. With these attributes and its rich heritage, India can make a substantial contribution in this field and eventually lead the world on the path of sustainability.
Less than a hundred years ago, Industrial revolution came to India and changed the many of traditional sustainable practices in Indian buildings. The insatiable thirst for progress and comfort-at-any-cost altered the equation with nature forever. Concrete, steel, aluminium, glass, and later plastics became the dominant construction materials, beyond stone and wood of yesteryears, Power supply, artificial lighting, water supply and disposal, thermal environment control within built-environment, are no longer the luxuries but are the necessities today. Over the years Indian architects are striving hard for striking a balance between the two extremes i.e. (1) providing modern amenities and comforts, and (2) reducing the negative impact of buildings on the natural environment. In the light of the above, the author presents a case study of one building- Punjab Mandi Bhawan, Mohali, India- which is incidentally designed by him.
PUNJAB MANDI BHAWAN, MOHALI:
Punjab State Agricultural Marketing Board is a semi-government corporate body established in 1961 with an objective to control and supervise the marketing network of sale, purchase, storage and processing of agriculture produce in the state. It is also a local authority with power to acquire, hold and sell property.
Earlier the Board was functioning from its own head office building in Sector-17, Chandigarh. With the growth of its activities and increase in staff strength, its office space became inadequate. More so there is acute shortage of parking space around it. The Board thus decided to construct its bigger and efficient corporate office building in Sector-65 A, Mohali adjacent to Chandigarh.
The new Head Office Building becomes part of large multi-utility complex comprising state-of-the-art fruit and vegetable market, commercial shops and showrooms established by the Board on a 20-acre plot. The Head Office Building is located on a plot of two acres on the south-west fringe of the complex. It is approachable from two sides, one from main road on north-west and the other from side road on the south-west side.
Challenges before the architect were:
- To design the office building which will match in comfort and ambiance with modern corporate offices being built now-a-days.
- To evolve an architectural vocabulary which will be a blend of those of Corbusian era as well as latest trends in office buildings viz-a-viz new materials and technologies?
- To make building sustainable / energy efficient and portray these measures on its exterior and interior expression.
The building is located on a plot of 2.08 acres (10,067 square yards). It has an area of 152000 square feet on six floors in addition to 57000 square feet in the basement. Covered area on ground floor has been kept minimum that is 24950 square feet. Thus the ground coverage is only 27.5 per cent. Out of the remaining 72.5 per cent open area minimum has been kept for vehicular movement and surface parking leaving sufficient area for green parks. These parks are envisaged to improve the micro climate around the building.
Basement is meant for parking of 150 cars and requisite services. Two circular ramps provide ingress and egress to the basement. The ground floor accommodates mainly entrance foyer, multipurpose hall, and miscellaneous services like bank, health clinic, gymnasium, maintenance stores etc. all the main offices are on upper five stories.
The built-form of the office building has been evolved ingeniously keeping in view all the constraints and goals. In plan, the block is fragmented into three blocks. Two square blocks of 75 x75 feet size each at the ends have been rotated to an angle of 45 degrees. By doing this major portion of the office building made to fall in north –south direction which is considered good orientation. These blocks which accommodate the major chunk of the offices draw natural light mainly from north or south side. East and west facades have been made largely blank. The central block which accommodates rooms of senior officers remained in south-west and north-east directions –the orientation dictated by the lay of the plot. Out of these two directions, the north-east side is considered good as it receives morning sun which is always welcome. Hence no special treatment was required. The unwanted sun on the south-west side has been cut off by a combination of vertical louvers and horizontal roof overhangs. This vocabulary has been inherited from Le Corbusier as the architect wanted to incorporate it in the design of this building as a mark of reverence to the master especially when it falls in close vicinity to his works.
As per the client’s brief given to the architect, the building has to incorporate the latest innovations for human comfort and ambiance. As a result the architect has to go in for a fully air conditioned building with ultra modern gadgets, lighting, furniture etc. Since the building has to be hi-tech and fully air conditioned the need to incorporate sustainable architecture / energy efficient measures becomes even more.
Saving energy through passive and active means
The following measures were taken to reduce the energy consumption in the building:
- Moulding and orienting the building in right direction.
- Exploring the concept of mutual shading.
- Minimizing the penetration of sun by vertical louvers and horizontal roof overhangs.
- Emphasis of natural light.
- Drawing maximum day light from north and south directions.
- Making east and west facades predominantly blank.
- Use of cavity walls on outer façade.
- Use of double-skin solar control glass (6mm+12mm+6mm) which blocks upto 73% of solar heat by reflecting it to the outside.
- All solid portions of external façade are clad in aluminium coated panels (ACP) which also reflect the solar heat outside. Also the gap in between the structural wall and cladding acts as cavity which further cut off the solar heat.
- Special efforts have been made to cut off the heat of sun from terrace. Use of foam concrete has contributed a lot in this regard.
- Incorporation of building management (BMS) and Light Management System (LMS) for optimal use of air conditioning and artificial lighting.
Efficiency in using water and managing storm water
While designing the building, efforts have been made to use the potable water very efficiently. All the fixtures and fittings in the washrooms kitchens and pantries have been selected with a view to minimize the use of water. Likewise the rain water has been managed quite effectively. A sufficiently large underground rain-water collecting tank has been constructed in the front lawn. The entire rain water from the flat roof terrace, plaza and paved areas at ground floor is being collected in this tank. This water is then used for irrigating the landscaped areas around the building. The average annual rainfall in this region is 1110 mm, so sufficient water is available for the purpose. This way the potable water (which uses lot of energy) is saved to a large extent.
Improving indoor air quality, and enhancing productivity
While designing the building sincere efforts have been made to create a healthier, enjoyable, comfortable and more productive work environment inside the building. Such environment incorporates good air and light quality, views to outside, comfortable temperatures, minimal noise pollution and low-toxicity ambiance. Good indoor air quality has been ensured by adequate intake of fresh air through mechanical air handling systems. It is a well known fact that most people prefer to work in natural light and have access to outside views. Special emphasis has been laid on providing natural light in all work areas as well as circulation areas. Fenestrations /glazing have been provided so judiciously that almost all areas get natural light throughout the day. Even the inner circulation areas are well lit with natural light. One will notice that on any given day, in a fair-weather, there is very little dependence on artificial light. This has been achieved by avoiding very deep areas, that is, away from external glazing. A full-height atrium in the centre is top-lit through a giant skylight fitted with translucent poly-carbonate sheets. This cut-out together with stairwells (which also abut external glazing) are sufficient to provide adequate natural light in the central circulation areas.
Work stations have been accommodated in open halls in the ends. These halls receive abundance of natural light from all sides. Each and every work area also gets natural view to the outside. Another major factor to indoor environment quality is temperature control. It has been taken care of fully with latest provisions like central air-conditioning, heating, temperature control devices etc. Noise can interfere with concentration and conversation and cause fatigue, irritability, headaches and stress. Special efforts have been made to minimize noise in the interiors so as to create workable and pleasant work place. Double-skin glass and cavity walls on external sides cut off the outside noise to a maximum extent. In the interiors, false ceilings have been provided in semi-perforated mineral-fiber sheets which absorb internal noise adequately. Besides the above, special emphasis has been laid on selecting the materials used in interiors which emit less volatile organic compounds and are thus less harmful to users’ health.
Reducing waste, construction materials, pollution and environmental degradation
The building is constructed in reinforced-cement-concrete frame structure with brick in-fill walls. These materials are locally available, durable, maintenance free and easy to use. Apart from this, these materials generate very less waste during construction. The concrete was prepared in ready-mix plant temporarily located at site and was being prepared as per exact requirements. So there was absolutely no wastage. The broken bricks produced some waste but this was used underneath the floors as brick blast.
External finishes of the building include aluminium-coated panels, toughened-double-skin glass with aliminium frames. Aluminium and glass are, no doubt, materials with high embodied energy, but their application have been preferred due to the following reasons:
- These materials contribute to lower operating requirements.
- These materials can more easily be reused and recycled if required in future.
- These materials will significantly extend building’s life.
Use of wood has been completely eliminated as timber extraction from forests has the potential to cause habitat loss, species extinctions and to displace indigenous people from their lands.
All false ceilings in the building are in gypsum board and mineral-fiber sheets. Both these materials are recyclable. In flooring, either granite stone or vitrified tiles have been used. These materials are very durable, hard, maintenance free and do not absorb dust, thus remain clean. All the internal partitions are in locally made clay bricks with cement plaster and good quality paint.
Improving the micro-climate by landscaping the surroundings
Efforts have been made to improve the micro-climate by landscaping the earmarked open spaces around the building besides due inputs have been made to minimize the impact of development on natural environment by simple measures such as protecting the top soil, landscaping with local native plants, minimizing soil run off during construction and control the water flow across the site. Social and visual amenity has been improved by allocating space for lawns in the site. These lawns are ideal places for community interaction amongst the staff during lunch breaks. Apart from this these landscaped areas add grandeur to the built environment and make it more productive, colourful, and attractive. Since the plot area is limited there is little space for big trees. Therefore some indigenous trees have been planted along the periphery. When fully grown, these trees will provide shade to the driveways and protect the building from harsh summer sun.
The building is a showcase of architect’s accumulated philosophy and incorporates salient features like ‘strict geometric order’, ‘symmetry’, ‘clarity in structural systems and services’, ‘use of contemporary materials and technology’.
- Location: Sector -65 A, Ajitgarh, Mohali.
- Area of plot: 2.08 Acres.
- Covered area: 2, 09,335 Sft.
- Covered area on ground floor: 24950 sft.
- Ground coverage: 27.5 per cent.
- Architect: Sarbjit Singh Bahga, Punjab Mandi Board, Chandigarh.
- Project team: Baljit Kaur, Kulwinderjeet Kaur, Ravinder Kaur, Parwinder Kaur, Deeksha, Darshan Singh.
- Contractor: Deepak Builders, Ludhiana.
- Structure: Harbhajan Singh, Techpecific, Mohali.
- HVAC: Anuj Aggarwal, Ambience, Panchkula.
- Electrical: N.K.Jain, Panchkula.
- Networking: R.K.Dhanda, Ludhiana.
- Project coordination and supervision: Engineering Wing of PMB headed by Chief Engineer R.P.Bhatti.
- Cost: Rs. 66.00 crores.