Green Technologies for Buildings Dasarathi GV (normally called Das)
DisclaimerI am not any of theseCivil engineer, Architect, Environmental engineerJust a dumb mechanical engineer who used his knowledge of mechanical engineering and lack of money to build an environment-friendly house.What I do for a livingFounder-DirectorCadem Technologies Pvt. Ltd., BangaloreMake software products for Computer Aided Manufacture
What is environment-friendly construction ?Popular definitionReducing energy and water consumption.- rain water harvesting, water recycling, solar energy.Expanded definitionReducing construction material + reducing energy and water consumption.
Problem 1 – Overdesigned structuresHow many years will this structure last ?How many years will it be allowed to last ?Average house is built to last a couple of thousand years, but is typically broken down in 25 years because the next generation’s requirements have changed.
Problem 2 – Skewed prioritiesEssentials - water, power, fresh air, greenery.Rain water harvesting, grey and black water harvesting, solar panels for power, trees.Non-essentials : Floor tiles, expensive walls, unnecessary concrete decor, jacuzzi.We spend on non-essentials. If there is any money left over, we spend on essentials. Should be reverse.
The fixExtend the tenets of environment-friendly living to construction.Reduce, Reuse, RecycleReduce : Reduce the consumption of materialReuse : Reuse an already used material, as it is.Recycle : Change the form of an already used material by heat, chemical reaction, mechanical force.
Our current thinkingWhat is this ? Construction waste.What is this ? Nice flooring
What we should thinkWhat is this ? Reusable construction material. Waste of material,What is this ? money, time.
Ideas for Reuse, Reduce in ConstructionUsed in a home thats 2 years old and still standing.
Reduce 1 – No concrete roofBamboo corrugated sheet instead of concrete roof.Concrete roofs trap heat during day, radiate it at night, hence get hot.Bamboo roof does not trap heat.
Reduce 2 – No airconditionersFans instead of air-conditioners.Because no concrete roofs, no walls, lots of windows.
Reduce 3 – No exhaust fan in kitchenNatural draught instead of exhaust fan.Opening above the kitchen platform for exhaust.
Reduce 3 – No flat, smooth walls0.25” plaster instead of 1.5” plaster on walls.Walls are ordinary (not wire-cut) brick. Our walls are not flat, undulate with the shape of the bricks.Cement and sand for plastering reduced by 75%.
Reduce 3 – No tiled floorsPlain grey cement floors instead of tiled floors.Saving : Rs. 2 Lakhs.
Reduce 4 – No wallsWalls are meant to keep the weather out.Windows are meant to let the weather in.Bangalore has pleasant weather through the year, theres no need to keep it out. Hence no walls.Bonus : Birds and animals for company.
Reuse 1 – Wood from packing casesWood : Pine wood from packing cases.
Reuse 2 – Glass from demolished buildingsGlass for walls, windows : 75 % from demolished buildings.
Reuse 3 – Reused toilet fittingsCommodes, washbasins, taps showers from demolished buildings.Fittings for 2 toilets cost Rs. 7000. New would have cost Rs. 50,000.
Reuse 4 – Reused kitchen sinksKitchen sinks from demolished buildings.3 sinks cost Rs. 5000. New would have cost Rs. 25,000.
Reuse 6 – Discarded paving stones from footpathsGranite paving stones in garden are discards from citysfootpaths – they were replaced by tiled footpaths.Savings : 90 %.
Reuse 7 – Rain water harvesting, grey water harvestingRain water harvesting tank capacity 20,000 l. - 4 times thelegal requirement.Grey water harvesting – water for garden.Black water harvesting proposed.
The net resultConstruction cost : 40 % of normal. Rs. 17 Lakhs.Construction time : 50 % of normal. 7 months.Aesthetics : Kachra house or Kuppe veedu was theHouse of the month in a home interiors magazine.
Just remember these1. Build to last 25 years, not 2500 years.2. Prioritize essentials - water, power, fresh air,greenery. Spend on essentials. If there is any money leftover, do not spend on non-essentials. Scale up theessentials – more solar power, more rain waterharvesting.3. Build to impress yourself, not your neighbours.4. The principles used in my home are universal. Canbe used in any building – home, office, school, hospital.
for listening patiently to me, and not falling asleep. More about the house here : www.lowcarbonlife.in