Nature has all the answers, demonstrates Sourabha. Built in 1994, the house runs completely on rain water, hasn’t paid the water bill in 19 years, heats and lights up on solar energy, cools naturally and has water bodies all around to refresh the air.
Of the total water our planet has, 97.5 percent is salt water in the oceans and 2.5 percent is fresh water. Every 20 years our water consumption doubles, and if this trend continues, water will no longer be a natural resource.
“Catch the rain where it falls, is my motto,” says A.R. Shivakumar, principal investigator- RWH, Karnataka State Council for Science and Technology, Indian Institute of Science, Bangalore. The scientist has many innovations and patents to his name and has been a big advocate of sustainable living and renewable energy in the last 2 decades.
“Rain water is the purest form of water,” believes this ‘rain-catcher.’ The family uses rain water for everything, even drinking, which is filtered using a simple silver sheet. “Given the water crisis we perennially see in Bangalore, I looked around to see if there are any other alternatives. There was the answer in the nature itself,” he says.
Bangalore receives rains of around 1000 mm in an year which is equal to 2.23 lakh litres per year in a plot of 60 ft X 40 ft. The rainfall is spread over 60 to 70 days throughout the year. One house’s requirement for the entire year is only 1.5 to 1.8 lakhs litres. So we have far in excess of what we need.
Shivakumar’s tryst with rain water began way back in 1994, when he began by constructing his 2400 sq.ft. large house using rain water. Being a scientist and innovator, he studied rain trends for the last 100 years and then came up with a comprehensive RWH system that could ‘catch every drop’.
The RWH system in Sourabha
Rainwater falling inside the plot is channelled to three applications: Roof top rainwater harvesting, Rooftop rainwater channelled to recharge ground water and percolation pits in the garden area to use surface run-off.
The majority of the rainwater falling on the roof (85%) is channelled toward the northern side of the house to flow in a tank of 4500 litres on the ground floor roof. A PopUp filter (an invention by AR Shivkumar), along with a stabilization tank, filters the roof water before storage. The overflow of this tank is allowed to rundown to an underground sump of 25,000 litres capacity. In case both the tanks are full, the rainwater is diverted to percolate into the ground to recharge ground water. Four recycled plastic drums are interconnected and buried underground with their bottom cut open. This acts as an infiltration gallery.
The remaining roof water is filtered and goes to an underground sump-2 of 10,000 litres. The water from both the sumps is used during non rainy seasons when the roof top tank is not available.
Grey Water Recycling
The small family of four, including Shivakumar’s wife Suma and two kids Anup and Abhineeta, requires around 400 litres of water per day excluding toilet flushing which is done by recycled water. Soap water from the washing machine is stored in an underground tank and pumped up to a tank on the roof and is used for flushing. The water coming out from the kitchen sink is used for gardening.
Living on 80 units of power every month
“There is no recurring cost involved in maintaining this standard of living except for electricity used for pumping the water,” says Shivakumar. The electricity consumption of the house is 80 units per month. The family not only preserves water but also follows a sustainable lifestyle. The lighting and heating load of the house runs completely on solar energy.
One part of the roof is converted into solar panels and a solar cooker is inbuilt into the house through a cooking unit that extends to catch the sun just outside the window!
The family also segregates their waste into wet and dry. While, the wet waste is used to prepare manure for the garden, the dry waste which is just 2-3 kgs per week is disposed off to BBMP.
Building a green home
In order to facilitate the use of natural resources as far as possible, importance was given to minute details while constructing the house. The walls are built using rat-trap design which provides good thermal insulation and also saves bricks, cement, and time. The cost of paint and plaster has been avoided by leaving the bricks and stone walls exposed. A large number of glass windows on the roof provides sufficient natural light and air throughout the day. The roof has been paved with clay tiles or painted white to reduce the impact of heat.
Another attractive feature of Shivakumar’s residence is the green space. There is an abundance of plants and trees which cover the house from all sides, preventing it from all kinds of pollution. Many birds and other creatures are regular visitors of the house. There are also many water bodies around the house like fish ponds and aquatic plants, so that the moisture gets added to the air and fresh air goes inside.
When talking about the cost of construction of the house, which was designed by architects Sudha and Jayshree, Shivakumar says that it was 20-30% cheaper than the normal construction. The estimated cost of construction of the house was around 8,50,000 when it was built in 1994. They have used the cheapest mosaic and clay tiles for the flooring and locally available stone for the walls. The same stone which was brought for the foundation has been used for the construction. They also have inbuilt stone furniture to avoid the excessive investment on furniture.
When asked about his favourite places in the house, Shivakumar mentions the RWH unit and garage. “I do most of my research in the garage, and if given a chance, I would double the place in the garage,” he says.
Sourabha is located at 3rd Main Road, Basaveshwara layout, Vijayanagar, Bangalore
Contact Shivakumar at- [email protected]
Bangalore’s greenest homes is a series on beautiful homes that have been built on strong sustainability principles – from natural building materials to efficient light and space design, water harvesting, off-the-grid energy energy, eco-friendly decor and furniture. And a lifestyle for the residents where less has meant a lot more.
This series on Bangalore’s greenest homes has been done with the support of ZED Habitats – the largest green residential developer in India today, and a leader in pioneering building technologies and management systems.
This piece is a part of ‘Paint Your Green‘ campaign for World Environment Day to “Bring Sustainability Home.”