From the name of a colour, green has come to signify a whole new world of environment-friendly products and innovations in design and architecture, says Maria Louis.
If we strip it of the hype and hoopla that surrounds it especially in the month of June, when we celebrate World Environment Day with a vengeance, we will realize that what is considered green today has actually always been an intrinsic part of Indian civilization. Consider the jali windows and courtyards that help cool our interior spaces naturally, thus helping us to save our invaluable natural resources. Like other Indian concepts that have caught on in the West, to be later aped by India, green architecture too is seeing a revival in modern times.
Apart from mud and bamboo for construction, and solar and wind to power large-scale projects, a new-age material used in addition to age-old bricks is aerated autoclaved concrete (AAC) – a material that provides structure, insulation and fire resistance, all in one. Thanks to widespread awareness about the need to save energy, new technology like heat-resistant fly-ash bricks, heat-reflective or low-E glass, double-insulated glass, environment-friendly air-conditioners and HVAC systems are growing increasingly popular. The environment-conscious consumer wants contemporary space design, but demands green design solutions for homes and offices.
Another bit of good news for all those concerned about the legacy we leave behind for the next generation, is that green is the loudest-voiced concern of the Corporate Social Responsibility (CSR) movement in India, and companies now want to be seen on the Green page even if it means spending that extra piece of green paper. In the light of this, we draw attention to some path-breaking innovations that exemplify different aspects of green architecture.
Case Study 1
Three tiers for cooling
A column-free space is a dream that does not come true very frequently. When studying the site for the new corporate and administrative offices for Fem Pharma in Nasik, to be located over existing office space in a newly-covered area built using steel trusses and profiled steel roofing, interior designers Conrad Gonsalves & Associates realized that along with the dream column-free space came the challenge of addressing the extensive height and volume within which one had to suspend whatever mechanical services were required.
Since a sizable portion of the space had to be cordoned off into enclosed spaces for a large conference room, canteen and executive cabins, the idea of retaining the full height had to be abandoned and a false ceiling was introduced. Thanks to a user who was open to technology and committed to using energy-conserving systems, experts in natural cooling systems, Surendra Shah of Panasia, were brought in to design a low-energy system for air-conditioning with inspiration drawn from our heritage buildings that remain cool without using any energy.
The idea was to keep the building from heating up by the sun. Two techniques were used: (1) Barriers and (2) Drain. Then an appropriate energy-efficient air-conditioning system was designed that had two sub systems: (1) For sensible load and (2) For latent and fresh air load.
1. Isolation of the light roof. The light roof was attached with insulating gaskets and treated with a shiny material on the underside to act as a radiant barrier. Then, a false ceiling was planned that would isolate the huge volume of air contained in the trussed section of the space. Roof extractors using only wind power were installed to remove the heated air in the space above the false ceiling.
2. Heat-reflective paint was used on the external walls of the G+1 standalone structure.
1. Solar heat absorbed by the RCC portion of the roof and the façade was drained out by a welded grid of iron pipes containing water under vacuum connected to a heat exchanger that used cooling tower water. The water in the pipes was boiled under the vacuum, thus extracting the heat from the structure where they were buried under the flooring. The vapour was piped to a heat exchanger where cool water from a cooling tower condensed the vapour into liquid that went back to the grid. In practice, both the heat exchanger and the cooling tower were combined into one Heat Rejection Unit. During the day, the system blocked the solar heat from the roof. At night, it extracted the heat stored in the whole structure. This was the first tier of the three-tier cooling system. The second and third tiers were two separate mechanical cooling systems.
Medium temperature was set for meeting the sensible load only. This air was cooled to about 20°C using air-cooled ductable units and was distributed by insulated ducts placed above the false ceiling level. Since conventional systems had to be used and the required air quantity circulated, the cooling or refrigeration capacity of the units was in excess. Although this did not have an immediate installed cost benefit, the running cost is significantly lower due to its high evaporating temperature. The efficiency of this system is enhanced by the fact that the dehumidification is being taken care of by the third stage system.
A low temperature unit for fresh air and dehumidification cools the air to about 4°C. The system took in around 10% fresh air, mixed it with 10% of from the return air and dehumidified this mix – which was distributed using a Point-Of-Use air distribution network of insulated PVC pipes of low cross-section and terminated in adjustable outlets, much like those in an aircraft or luxury bus. This avoids inefficient air supply at 10°C at the ceiling being made to absorb the room load before it reaches the occupant at 22°C. The advantage of the fresh air distributed to the point of use is that it prevents its “dilution” with the rest of the recycled air being circulated by the medium temperature system, since the supply is within the occupants’ breathing zone.
The combined energy-efficiency of two tiers of this system is much higher, since the average evaporation is at about 15°C. The evaporation temperature of the single tier is anywhere between 2°C to 8°C, while the condensing temperature is the same. Since an air-conditioner pumps heat, its energy consumption is directly related to the difference in the condensing and evaporating temperatures.
So, by applying techniques that have been used traditionally in our heritage structures, in tandem with modern technology, the load on the system was reduced and the structure was kept cooler than the human body . The energy saving was estimated to be between 30% to 40%, while the air quality within the breathing zone was improved due to higher oxygen level.
User: Fem Pharma, Nashik
HVAC Design: Surendra H. Shah
HVAC Contractors: Opal HVAC Engineers Pvt. Ltd.
Interior Design: Conrad Gonsalves
Case Study 2
Moulded out of mud
by Renu Ramanath
Architect Eugine Pandala, based in Kollam, Kerala, has always been a staunch votary of mud, when it comes to environment-friendly building materials. Pandala’s experiments with mud as a construction medium had started during his student days at the School of Planning and Architecture, New Delhi, following an encounter with Hassan Fathy – the Egyptian architect and advocate of mud architecture, who had authored the book, Architecture for the Poor: An Experiment in Rural Egypt.
Owiyam, a retreat he built for a group of young Indian and German artists at Marayoor in Idukki district of Kerala, bagged him an award for Eco-Friendly Design in 2007 – which he shared with Yatin Pandya. Nestling among the rolling hills of Western Ghats at Marayoor and built entirely out of mud, thatch and rocks, Owiyam looks like it’s growing out of the surrounding boulders.
The building, less than 1,000 sq. ft. in area, stands on a seven-acre plot that was earlier a sugarcane field. The clients, who believe in living the natural way, wanted to restore the land to its former state as much as possible. The only intervention in the landscape was the construction of a rainwater harvesting tank. Soil and rocks excavated in the process were used for construction. A stream coming down from the top of the hill flows through this plot.
The cob technique, Pandala’s favourite mode of construction with mud, was adopted – as using large lumps of mud gives him the freedom to sculpt the walls in a free-flowing manner.
The highlight of the building is a wrap-around verandah that hugs the living space and bedroom, with a semi-open bathroom and a staircase leading to another living space upstairs. In the bathroom, a tap is connected directly to the stream winding down from the hill-top, and fresh water flows down straight from the source without any energy consumption. Natural boulders and pebbles collected from the site are used in the bathroom floor, while the clay tiles used in the living spaces and bedroom were all made on site by local craftsmen.
The boulders and stones project from the walls, adding to the rugged look. Mud is used for more than the walls, even the staircase and the built-in bed is sculpted out of it. Beeswax is used to polish the built-in bed. Locally available beeswax is used for candles as well, since the building has no electricity.
The roof is thatched, with bundles of sugarcane leaves (again, locally available) thatched on a frame work of timber. Perhaps the only extraneous material used in this construction is the panels of toughened glass for windows. This was unavoidable, as the heavy monsoon rain and wind lashing the region warrants strong protection. However, the adobe walls offer good protection against the dampness and chill in the rainy season and during winter. Adobe absorbs the available solar heat during the day, radiating the heat back at night.
Mud is the most fundamental building material used by human beings, points out Pandala. If judiciously employed, making use of the locally available soil alone, it causes the least damage to the environment. River sand mining and stone quarrying, two of the severe environmental hazards caused as a direct result of construction activities, can be reduced considerably if people are willing to experiment, believes Pandala.
“I’d call a green building something that is absolutely natural,” says the architect. “All traditional buildings, before the coming of cement, were natural or ‘green’ in that sense. You can’t paint a building green and call it a green building!” he quips. “True green should be true to nature.”
Case Study 3
From the bamboo grove
by Renu Ramanath
A ‘nature-friendly built environment’ is the motto for Kochi-based architects Jaigopal G Rao and Latha Raman-Jaigopal – who believe in starting from the home turf. Naturally, when they decided to experiment with the application of bamboo as a construction material, the starting point was the premises for Inspiration, their own office.
The construction took place during 2004–05, with no pre-set deadlines. Today, Inspiration’s 2,750 sq ft office in Eroor, a quiet suburb of the port town of Kochi, stands tall with its walls, floors and roof clad in bamboo. Here, bamboo replaces almost 70% of structural steel and cement. It is used in combination with more conventional materials, like reinforced cement concrete (RCC) in columns and ferro-cement beams.
The building has won an award in the ‘Urban Office Buildings’ category at the International Bamboo Building Design Competition at Hawaii in 2007 and a Hudco National Award in the Design Ideas Competition 2004-05.
The two-storeyed building is a framed structure, with RCC columns and ferro-cement beams providing the framework. Panels made by bolting treated bamboo on to frames are used to fill in the frame, forming walls. These panels can be plastered either on one side alone or on both sides. At Inspiration’s office, the panels are plastered only on the inside, giving a ‘green’ look to the exterior and a smooth finish to the interiors.
The same panels can be used with plastering for the floorboards as well. A normal red-oxide finish is given over the plastering.
The building stands on stilts, over an artificial water body created for rainwater-harvesting that helps to cool the surrounding air. The stilts are used to reduce the chance of dampness seeping in, as well as to protect against attack by rodents and insects.
This office needs no air-conditioning, with the ample cross-ventilation and the presence of bamboo helping to reduce the internal temperature by almost 4–5 degrees compared to the outside. The surrounding water body also helps to cool the air entering the premises.
“Bamboo fits the bill perfectly, in terms of non-energy-intensive material,” points out Raman-Jaigopal. Bamboo harvested from a 60 ha plantation is enough for constructing 1,000 houses per year. If timber is used for the same number of houses, it would eat into 500 ha of forest.
The fastest-growing plant species on earth, bamboo is a high-yielding, renewable material resource. Its natural production (without any chemical intervention) involves no excess energy consumption. No polluting agent need be used in the growth of bamboo, and it absorbs the maximum quantity of CO2 than most other plant species. Even the preservative treatment can be done without toxic or environmentally-hazardous materials.
Its low weight makes bamboo ideal for earthquake-prone zones. Using bamboo can help to reduce the entire dead weight of the building by 1/3rd of a similar building with conventional masonry walls and RCC slabs. Almost 25% of the bamboo needed for the construction was obtained from the site itself. Since this was their first project, all work was done on site – including the cutting and treating of bamboo. Today, however, Inspiration uses pre-fabricated bamboo panels.
Inspiration had already used bamboo quite successfully for non-building but structural uses at many other sites. Bamboo was used as reinforcement for road base, on an area of 6,000 sq m (at Hotel Sarovaram, Ernakulam), and also for 20,000 litre capacity water tank, 14 m x 4 m road culvert and retaining walls (at Chitrakutir, an artists’ village near Mumbai).
For technical support, they sought the guidance of two bamboo experts, K.R. Datye and V.N.Gore, of Geo-Science Services, Mumbai – who have been in mainstream construction for a long time, but have now turned to alternative building materials and structural engineering application of alternative materials.
Case Study 4
Lessons in energy-efficiency
by Sudha Pillai
Jnana Jyothi, a Vedic Center and Patashala in Bangalore where Vedas are taught systematically under the pedagogic principles of the age-old gurukul system of education, is being set up by the Namma Sampradaya Trust. The project will be fully operational by the end of 2009.
The Vedic centre is designed and constructed by Bangalore-based Rare Earth Developers, a sustainable development company started by three engineers, Ajay Chandrashekar, Basavaraj Deodurg and C.A. Thimaiah. “The company roped in Satej Alur of Alur Associates to conceptualize the project with system integration of sustainability and green technologies,” says Pradeep Kumar Rao, VP Projects, Rare Earth Developers.
The concept for the design revolves around the fundamental Hindu motif, the Swastik – symbolizing `well being’, with the four dots in the four quadrants symbolizing the four basic elements: earth, water, fire and air.
Each of the four legs of the swastika will contain one function pertaining to the Patashala and will also be linked to one basic element. The central vertex will consist of the main meditation hall, pyramid in shape, to harness the maximum energy possible.
“Each block is being constructed using energy-efficient materials designed to resonate with Vedic chants and sutras. The endeavour is to diminish the use of conventional construction materials and use natural materials. However, the centre will be technologically advanced. It is a self-sufficient design in terms of water usage, power, etc.,” reveals Pradeep Kumar.
Natural and eco-sensitive building materials are being used, which age well and require less maintenance. The centre will make efficient use of space, light and ventilation and will be self-sufficient in terms of power and water usage by tapping Solar Energy, a clean source of energy.
Pradeep elaborates, “The energy needs of the campus were studied (Lifecycle and Usage pattern study) according to the location of the project, placement of the buildings and their power requirements. The study revealed that the campus would need 21 KW/hr. The revised power consumption was brought down by 8.5 kilowatt hour (KWHr) by use of customized LED lightings, which was exclusively designed and manufactured for the campus. The power requirement was plugged on to solar energy.”
By using the LED lightings, the power consumption is brought down by 70%. That also brings the cost of the equipment down to 50% (Rs. 10 lakh) as compared to conventional lighting systems (CFLs). The return on investment is brought down from 35 years to 6 years by use of LED lighting and tapping solar energy. The life cycle of these lighting systems is 10 times higher than the conventional systems life span.
Rare Earth is also proposing a windmill of 1.5 kilowatt for power generation, which will take care of 25% of the power needs of the campus. This Hybrid system of power generation is the clean renewable energy, which is virtually off-grid campus from the main power grid. The grid power is used only for pumping the ground water (bore well) to the underground water tank. Solar pumps are used to pump the water from the underground water tank to the overhead water tanks for consumption. Provision is also made to pump ground water through solar energy.
Instead of geysers, solar energy is used for heating. “We have used evacuated glass tube collector water heating system, which heats water faster with minimal heat loss,” says Pradeep.
Zero-waste Bio kitchen (Briquette Kitchen) and solar cooker and Sarai Cooker are used for cooking at the campus. Provision is made for a biogas plant which will generate gas for cooking.
Water management is done through rainwater harvesting, recharging ground water, ground water recycle and re-use. The Vedic Patashala is testimony to the principles adopted by new-age green warriors such as Rare Earth Builders, and highlights what could be possible in future.