Sustainability may not be what the world wants, but it may be what it needs. Consider the scale of the problem that confronts us. When the authors of this article were teenagers, the population of the world was about 3 billion people. Now that we are middle-aged, it is 6 billion. By the time our children are middle aged, the
population will be 9 billion. (data from U.S. Bureau of the Census (1999) Report WP/98, World Population Profile:1998, U.S. Government Printing Office, Washington, D.C. p14) Confronted with this three-fold increase in population, the world has not got any bigger. It has no more resources or land or water than it had in the
1960s, but it has to sustain all those extra people. This may not be too big a problem for countries whose citizens do not make exorbitant demands on the world’s life-support systems, but if those additional people live in the United States, Europe, Canada, Australia, Japan and the other highly developed economies, their demands for
goods and services will result in huge increases in the demand for resources from the world’s limited stores.
The problem at home
In Australia, as in most countries, the domestic sector of the economy consumes more energy and resources than the commercial sector. The CBD towers may look spectacular, but it is people’s homes that are causing more damage to the environment, and making the larger contribution to climate change. Another large part of the problem
is related to transport, and again, it is the domestic part of transport, the private car, that causes the larger part of the problem.
Those of us who design the built environment have a duty to consider sustainability, because we are the designers of artefacts that have a long life. Your new computer is outdated the moment you buy it, and you will discard it after only three years. The car you buy today may have fallen apart in 15 years’ time. Politicians need
to consider only the time up to the next election, they are not able to take a long-term view because they may not be re-elected. The average house, on the other hand, even here in New Zealand where they are made entirely of timber, has an economic life in excess of 100 years. This means that the houses we build today will be here long
after oil and natural gas are no longer available as fuels, yet we still design houses as though the resources are there to enable them to be sustained into the long-term future. In 50 years’ time there will be very little in the way of fuels to heat, cool, light and power the homes of a rising population, in Australia and worldwide.
What’s the solution?
One way to buy more time, is to slow down the rate of demand for resources. This does not require the invention of new technologies or the spending of years on research, it involves putting into place some of the things that already exist in the marketplace. The government currently provides a grant for new homeowners; it would not
be too hard to insist that this grant would be paid only to buyers of houses that made use of some no-cost or low-cost features to reduce their life-cycle impact on the environment. It is reasonable to argue that we should not be building today houses that are thermal slums; too cold in winter and too hot in summer. This makes poor
economic sense. If new houses are built in ways that lessen their environmental impact (and that lessen the costs for the householder) it will stimulate demand for these same features to be applied to existing houses.
Many of the changes that make a house work better are free. It costs nothing to orient a house to the north so that it can collect the winter sun; it costs nothing to plan the rooms and the windows so that they can receive sun in the winter and are shaded in the summer. It costs nothing to install a floor slab that can store some of
this free heat for use after the sun has gone down. In the North of Australia there are plenty of houses that might make sense in Hobart, but which can be made comfortable in Darwin or Cairns only by air conditioning. But it is possible in hot climates to build houses with proper shade and ventilation that do not need to be air
conditioned. None of these design changes has any cost, none needs any great skill; all that is needed is the desire to do it.
There are further changes that may have small costs, but that are rapidly cost-effective for the householder – these should not really be options on new houses, they should be part of the Building Code, in the same way that seat belts are required in cars (although they add cost) because there are measurable benefits to society
from their installation. Some of these changes, such as the fitting of appropriate insulation in walls, roof and floor, are not always easy to apply to existing houses. Others, such as the fitting of AAA-rated taps and shower roses, or the use of compact fluorescent globes for lighting, can be applied cheaply and easily to all houses.
One very simple example that would make a big difference would be to require the use of solar water heaters for new houses. Nearly a third of the greenhouse gas emissions from Australian houses are the result of the energy used for heating water, yet a solar water heater will provide at least half the hot water needs of a house, and
can provide up to 90%. In Israel the Building Code requires all new dwellings to have a solar water heater, with the result that there is a thriving industry making the heaters, and they are cheap enough to be used in existing houses as well. They are even used on blocks of flats. Australia could do this; its population is more than
three times that of Israel, giving a suitable size for the development of a market. At current prices the additional cost of a solar hot water service compared to a standard one could be covered by making the house about two square metres smaller in floor area – the money saved by not building those two square metres will pay for the
Water is a resource which is scarce in most of Australia. Yet we treat water as though it is free and endless. Huge savings can be made in water consumption, by collecting rainwater and using it for garden watering, toilet flushing and laundry, none of these activities really needs purified drinking water. Again, the Building Code
could require that new houses have water tanks so that the demand for water from reticulated services is reduced.
The answer to sustainability lies in our behaviour as well as in our technology. The largest sector for greenhouse gas emissions from transport in Australia is private cars, which produce about 42 per cent of the emissions related to transport (data from www.greenhouse.gov.au/inventory/facts/03.html).
Yet the fuel efficiency of cars in Australia has improved by only 2 per cent since 1991. Many manufacturers are making cars that are far more efficient than the current average for Australia of 11.7 litres per 100 km. The Volkswagen/Audi Group in Europe already markets four-seater cars using conventional diesel engines that achieve
consumption of 3 litres per 100 km. But we do not choose to buy these cars. We want big sedans and four-wheel drives. We value our freedom of choice in the marketplace. By choosing big houses and big cars we have chosen to eliminate the Pacific island state of Tuvalu, whose population is being evacuated to New Zealand because of sea
level rise caused by global warming. (Simms A. (2001) "Farewell Tuvalu" The Guardian Monday October 29). Tuvalu has a population of 11,000 people, but it will not be long before sea-level rise makes Bangladesh uninhabitable, and the population there is 20 million. Will Australia welcome these refugees of climate
Do we want to do it?
It is quite possible in all parts of Australia to construct a "house with no bills", which would be comfortable without heating and cooling, which would make its own electricity, collect its own water and deal with its own waste. Its impact on the environment would be minimal, and it would produce no greenhouse gases.
These houses can be built now, using off-the-shelf techniques. It is possible to build a "house with no bills" for the same price as a conventional house, but it would be smaller, with a floor area for example of 120 square metres instead of 180. In just the same way, we can reduce the damage we do to the environment if we
make the choice to buy a small efficient Audi for the price of a large wasteful Holden. Both of these options still allow us to have a house and still allow us to have private transport. Are we prepared to make even these small changes in our lifestyle?
In the end, sustainability is our choice. We can choose to do it, or we can choose to ignore it. But the problem will not go away. The populations of the countries that suffer from the effects of our
unsustainability do not have our choices.
Brenda Vale and Robert Vale were the overseas speakers for the Australian Greenhouse Office’s recent sell-out lecture tour "Sustainable Houses: Moving to Mainstream" which was presented to packed houses in ten cities across Australia. Details on www.yourhome.gov.au.