Humanity currently faces its greatest challenge ever - to support continued growth in living standards whilst reducing global warming and without increasing demand on diminishing natural resources. This challenge is now driving change at all levels through government, business and civil society.
More and more business and government leaders are grasping the great opportunity - if we invest in innovative design and technology, and if we only 'cease to be stupid', we can cherish the natural environment alongside social and economic progress.
In Europe the largest share of energy used in buildings is heating. Insulation and good thermal design can dramatically reduce heat loss and help reduce global warming. The government has implemented incremental improvements to building regulations but this is not fast enough and the savings through retrofit are limited. Large savings can be achieved through a program of replacement new-build to the best available standard.
For example; a house built in 1990 will use between 150 - 400 kW.h/m2.yr for space heating. This can be reduced to around 10 kW.h/m2.yr with a new build SIP home with a U-Value of 0.2 W/m2.k or lower.
Achieving low energy demand in use is the most important factor. Embodied energy is especially misleading for materials and equipment, which are critical to energy efficiency. Ensuring performance over the life time of the property is much more important.
Low Embodied Energy
The tests carried out by TRADA shows the embodied energy of timber-based building products is up to 60 per cent lower than masonry alternatives.
|
KWh |
|
KWh |
% Energy Saved Using Timber |
Timber Frame Wall |
7450 |
Lightweight Concrete Block Wall |
12816 |
42% |
Timber Ground Floor |
2669 |
Concrete Slab Ground Floor |
6922 |
62% |
Timber Intermediate Floor |
2947 |
Concrete Intermediate Floor |
8312 |
65% |
Timber Windows |
1024 |
UPVC Windows |
7872 |
87% |
Total |
14090 |
Total |
35922 |
60% |
Once we have reduced our energy consumption we must look at more sustainable methods of producing our energy. At present almost all of our energy is adding to local air pollution, acid rain, damming of rivers or nuclear waste increasing the risk of global warming. Better ways of producing our energy is by using natural resources such as solar and wind energy which can be successfully incorporated into the building design.
The way in which we build is also having a high environmental impact. 70% of building materials we commonly use - raw stone, gravel, cement or sand; are adding to landscape destruction, toxic run off, deforestation, air and water pollution from processing. (16% of our total water withdrawals are used in the processing of these materials adding to water pollution.)
On site waste generation is adding to landfill problems, such as leaching of heavy metals and water pollution.
Poor indoor air quality of traditional built homes are adding to high incidence of sickness - lost productivity in tens of billions annually. A £1 billion annual health bill is attributed to poor housing.
Economic levels of insulation are usually judged on simple payback, which gives a poor indication of advantages. If considered instead by return on investment in better insulation levels, this can produce a large return on investment by reducing running costs. As important is that the decision must consider the whole building system; for example whole heating systems can be omitted as design improves, a saving which will pay for improvements to insulation and ventilation systems.
Energy efficiency and caring for the environment in which we live does pay dividends. Deutsche bank cut CO2memissions by 50% and saved €10 million from 1995 - 2002, BT has saved £119 million since 1991 through energy efficient policies. Every home owner could benefit from reductions in fuel bills by more than 70% if they were to invest in new and evolving building techniques and renewable energy - homes don't have to cost the earth. |
