The
definition of an ecohouse is an environmentally low-impact home, designed with
sustainability in mind and built using materials and technology which reduce
its carbon footprint and lower its energy needs. This seems both logical and
necessary, the question is whether this standard can be approached in the UK,
on a practical and financial basis.
The current
situation, with the building of a few homes using German Passivhaus ideas is a
laudable start, but if the construction industry really wants to make a difference to the
environmental impact of its activities, a radical change of thinking is needed.
It should no longer be acceptable to
continue to build standard brick and mortar homes, apply cavity wall insulation
and a few solar panels and expect that to be enough. Spread over 100 or more
years the carbon footprint of the construction of an individual house may not
look particularly high, but climate change is here, now; we no longer have 100+
years to work on it.
Materials
used in standard house building are not obviously compatible with sustainable
construction. For example, the use of concrete could be a major issue. Weight
for weight it is the second largest quantity of material used in house building
after bricks. Concrete is made from 10 to 15% Portland cement, the manufacture
of which requires a high input of energy resulting in one tonne of greenhouse
gas emissions for every tonne of cement produced. Technologies are being
researched to reduce this impact, including putting the CO2 back into the
product, but these new materials are not yet widely available.
So, the
question is, do we need to go back to mud floors and wattle and daub walls?
Maybe the answer is another question; why not? We now know that we can build with
wood without destroying the rain-forests. Forget tree hugging, timber can be sustainable, timber framed homes are increasing in
popularity and in the right circumstances, other old technologies are also
highly sustainable. Where hazel and willow grow easily, they can be coppiced
for construction, used as withies for wattle panels and they regrow rapidly. Daub is just any local,
clay subsoil. For projects in the right area, such locally available materials can
make building highly sustainable without going in for industrialised
Passivehaus type technology.
While some developers may baulk at the time/labour equation involved in sourcing/using such localised resources, not to mention having to retrain staff in unfamiliar techniques, maybe priorities need to change. We don't have anything like that 100 years to to put things right. The issue goes way beyond housing, but it would be a great place to start. All the new-build houses which are urgently needed in this country should be not just more bricks and mortar, but genuine eco homes.
While some developers may baulk at the time/labour equation involved in sourcing/using such localised resources, not to mention having to retrain staff in unfamiliar techniques, maybe priorities need to change. We don't have anything like that 100 years to to put things right. The issue goes way beyond housing, but it would be a great place to start. All the new-build houses which are urgently needed in this country should be not just more bricks and mortar, but genuine eco homes.
*
Sources include:
No comments:
Post a Comment