Presentation on 'Environment-friendly construction' in Greentech Seminar at Avinashilingam University, Coimbatore

1. Green Technologies for Buildings
Dasarathi GV
(normally called Das)

2. Disclaimer
I am not any of these
Civil engineer, Architect, Environmental engineer
Just 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 living
Founder-Director
Cadem Technologies Pvt. Ltd., Bangalore
Make software products for Computer Aided Manufacture

3. What is environment-friendly construction ?
Popular definition
Reducing energy and water consumption.
- rain water harvesting, water recycling, solar energy.
Expanded definition
Reducing construction material + reducing energy and
water consumption.

4. Problem 1 – Overdesigned structures
How 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.

5. Problem 2 – Skewed priorities
Essentials - 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.

6. The fix
Extend the tenets of environment-friendly living to
construction.
Reduce, Reuse, Recycle
Reduce : Reduce the consumption of material
Reuse : Reuse an already used material, as it is.
Recycle : Change the form of an already used material
by heat, chemical reaction, mechanical force.

7. Our current thinking
What is this ? Construction waste.
What is this ? Nice flooring

8. What we should think
What is this ?
Reusable construction
material.
Waste of material,
What is this ? money, time.

9. Ideas for Reuse, Reduce in
Construction
Used in a home that's 2 years old and
still standing.

10. Reduce 1 – No concrete roof
Bamboo 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.

11. Reduce 2 – No airconditioners
Fans instead of air-conditioners.
Because no concrete roofs, no walls, lots of windows.

12. Reduce 3 – No exhaust fan in kitchen
Natural draught instead of exhaust fan.
Opening above the kitchen platform for exhaust.

13. Reduce 3 – No flat, smooth walls
0.25” 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%.

14. Reduce 3 – No tiled floors
Plain grey cement floors instead of tiled floors.
Saving : Rs. 2 Lakhs.

15. Reduce 4 – No walls
Walls are meant to keep the weather out.
Windows are meant to let the weather in.
Bangalore has pleasant weather through the year, there's
no need to keep it out. Hence no walls.
Bonus : Birds and animals for company.

16. Reuse 1 – Wood from packing cases
Wood : Pine wood from packing cases.

17. Reuse 2 – Glass from demolished buildings
Glass for walls, windows : 75 % from demolished
buildings.

18. Reuse 3 – Reused toilet fittings
Commodes, washbasins, taps showers from demolished
buildings.
Fittings for 2 toilets cost Rs. 7000. New would have cost
Rs. 50,000.

19. Reuse 4 – Reused kitchen sinks
Kitchen sinks from demolished buildings.
3 sinks cost Rs. 5000. New would have cost Rs. 25,000.

20. Reuse 5 – Lamp shades from dust bins /
footpath
Savings : 75 % cheaper.

21. Reuse 6 – Discarded paving stones from
footpaths
Granite paving stones in garden are discards from city's
footpaths – they were replaced by tiled footpaths.
Savings : 90 %.

22. Reuse 7 – Rain water harvesting, grey water
harvesting
Rain water harvesting tank capacity 20,000 l. - 4 times the
legal requirement.
Grey water harvesting – water for garden.
Black water harvesting proposed.

23. The net result
Construction cost : 40 % of normal. Rs. 17 Lakhs.
Construction time : 50 % of normal. 7 months.
Aesthetics : 'Kachra house' or 'Kuppe veedu' was the
'House of the month' in a home interiors magazine.

24. Just remember these
1. Build to last 25 years, not 2500 years.
2. Prioritize essentials - water, power, fresh air,
greenery. Spend on essentials. If there is any money left
over, do not spend on non-essentials. Scale up the
essentials – more solar power, more rain water
harvesting.
3. Build to impress yourself, not your neighbours.
4. The principles used in my home are universal. Can
be used in any building – home, office, school, hospital.

25. for listening patiently to me,
and not falling asleep.
More about the house here :
www.lowcarbonlife.in