Q: There has been a lot going on in the last 12 months, as scientists become more and more strident in their warnings about the rate of global warming and the urgency of reducing the greenhouse agents released from fossil fuel combustion. The main driver for the sudden calls for accelerated change are that we are headed for more than 3 degrees of warming by 2100 if we follow current reduction targets, and there is virtually universal agreement that 3 degrees means catastrophe.
There is also general agreement that getting at least some of the major industrial nations like the US off fossil fuels in 10 years will be a major key to limiting warming to 2 degrees. Doesn't sound like much difference, but it is all the difference in the world. Australia's role in that is a function of our current contribution to global emissions of about 0.3 per cent, and the role we play as leaders in lobbying, technology development, and market uptake of new technologies. What can the design and building industry do to help?
A: To get off fossil fuels requires major strides in reducing energy demand in the first instance, and this is the first big challenge for our industry. If we do not make buildings that operate without wasting energy then everything else becomes much harder.
Passive design for thermal comfort is the key. Our residential buildings have the opportunity to reduce energy demand by up to 80 per cent, and 70 per cent in some commercial buildings. This is through passive and hybrid thermal design, clever integrated daylighting and artificial lighting design, and massive reductions in embodied energy through such things as 95 per cent recycled concrete (yes it exists now) and non-fired cement technologies (at least two exist right now, developed in Victoria and Tasmania).
Using natural ventilation (covered in a recent issue of BPN) in most climate zones will provide massive free cooling on an annual average. Controlled solar gain, especially in residential, will provide mostly free heating if it can be absorbed by thermal mass elements, and its heat is not lost through a leaky envelope. In short, the seven key elements of passive design, worked together in creative balance, give buildings a huge head start. They include:
1. Orientation — where’s north? Where's the good sun? Where's the evil sun?
2. Zoning spaces — how can we control air movement within the building, especially between levels?
3. Thermal mass — what materials can we place in the core of the building (not outside) to act as warm and cool batteries?
4. Shading — how can we control the solar access?
5. Insulation — how can we minimise heat flow through the walls, floor and roof?
6. Ventilation — how do we place openings to encourage cross ventilation and night purging?
7. Glazing — how do we design and specify the openings and glass type to work with one to six above?
Once we have reduced the thermal control loads to a minimum and maximised daylighting, we turn to renewable energy development to make up the remaining energy demand. This is where Al Gore's most powerful economic point is made: the US currently exports $2 billion every day importing oil and coal. That's over $700 billion every year, just for energy. That kind of money spent internally, developing the technology and infrastructure around renewables, is equal to the entire economic stimulus package George W Bush signed over to shore up their stumbling economy. Simply put, it makes most sense to spend on renewables rather than importing black stuff dug up by someone else. Barak Obama seems set to push this further.
For Australia, that is a two- edged sword, as we both import oil and export coal. But we must count the cost of seeing coal exports wind back against the benefit of not losing our coastline, not losing our grainbelts, and growing a global renewable energy knowledge stream. It remains to be seen if Kevin Rudd, Peter Garrett and Penny Wong will take the challenge to accelerate the rate of change needed. Heaven knows, we've told them.
The times they are a'changing, and so much faster than any of us thought possible.
Dick Clarke is principal of Envirotecture, which provides design and consulting services. He is an accredited building designer with 30 years experience, focusing exclusively on ecologically sustainable and culturally appropriate buildings. Clarke is director of sustainability and past president of the Building Designers Association of NSW.
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