Low Impact building

3 Mar

Once a month Green building lecture series are bringing insight into the better building industry. This month Cultivate.ie invited Tom Wolley to speak about Low impact building using natural materials.
As introduction Tom pointed out that a more holistic approach is needed in Green building. This should count for investors, architects, engineers, builders and planning officers. The reality is sadly on the opposite side and according to Tom only 10% of cohesion funds for Green building are used effectively. Causes of this are various, but first are the multinational companies manufacturing synthetic building materials. People are not really aware of danger these materials can pose to their health. Already in early 90’s there were reports published about carcinogenic properties of man made fibers like glass fiber and rock wool. Answer on the obvious question is profit. Big companies have big influence in government and health issues are still ignored.
Tom continued with few examples of dangerous materials still being widely used. One of these is DOW FROTH PAK which is a sprayed styrofoam system. In the safety data sheet you can have a read about its toxicity. A lot of controversy around DOW after they bought a factory where Bhopal disaster happened on December 1984. The gas MIC (methyl isocyanate) escaped and caused 6000 deaths and over injured over 500000. MIC is used in the manufacture of polyurethane foam. Most of the modern passive houses rely only on mechanical ventilation and when this fails toxic vapors from synthetic materials can pose real danger. Natural insulation options are free of these dangerous materials so choose this alternative. Another bad example of modern building system is dynamic cavity wall system from Jablite. The outside air is sucked trough insulated wall cavity and can raise temperature of incoming air up to 8°C. So you are getting warmer air with a mixed vapors of styrene, pentane, bromine (all considered dangherous by HSE) and some outdoor pollutants. Why not use natural breathable walls instead?
Here is a eye opening article about Greenwash in the building industry.
Cement production is responsible for 5% to 8% of global CO2 released into atmosphere plus huge amounts of fuels being used at manufacture. Use of recycled concrete (urbanite) as aggregate can do a difference.
New green ways of creating energy like wind and PV(photo voltaic) use great amounts of enery before they start to produce it plus they are very expensive.

We have to focus at maximum energy efficiency of our buildings with low embodied energy materials, that is what will make the real change in the future!

Tom’s guest cottage made from Hemp & Lime is a great example of natural building.

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