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Housing - low-energy

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Why our housing needs to be vastly improved

Derek Wrigley

 

Before considering the practicalities of either retrofitting an existing house or of building an efficient new house it is really necessary to consider why we are contemplating such action.

These papers [1] assume that :

  • we cannot, in fairness to future generations, continue to pollute the atmosphere and consume resources at our current (and increasing) rate
  • we need to change our habits now, not in 10 or 20 years
  • as the housing segment uses 12 % of Australia’s total energy consumption it is significant enough to warrant a major effort
  • lower energy consumption in houses that have been built or improved to be more thermally efficient will outweigh any increased consumption in construction or retrofitting
  • natural gas and electricity must inevitably rise in price to a level sufficient to cause hardship to many people
  • the sun is the only freely available source of renewable heating for houses
  • the knowledge is available to build solar-efficient houses, but if this is to happen it will require public understanding, political will, and the rapid development of trade skills
  • the consequences of doing nothing are not acceptable.


Climate change - Predicted changes in our climate are already happening and will almost certainly get worse. This will undoubtedly cause house owners to reconsider their values and initiate some response, but if society waits for this to happen then it could well be too late to prevent our CO2 saturation in the atmosphere from climbing above the 440ppm currently regarded as a maximum safe level. Beyond that level it is predicted that positive feed-back will occur, resulting in catastrophic consequences for future generations. Such changes will be impossible to correct.
Our generation must accept the responsibility for seeing that this does not happen – as we, in our innocence, have exacerbated these changes.

 

Housing can be grouped into two main areas for active correction:

1. Existing occupied houses – estimated at around 95-98% of total housing stock at any one point in time. Most of these houses can be regarded as sub-standard in thermal efficiency and have rarely been designed or oriented to take effective advantage of available (free) solar radiation. Many are in the form of apartments or flats or are rented, making their conversion into solar effective dwellings limited, but some improvements can be made in virtually all cases.

Many separate houses are surrounded by large shading trees on their own or on neighbour’s blocks. These restrict solar access but owners may be unwilling to remove them.

Despite all the problems listed above, retrofitting existing houses is probably the quickest, most effective, lowest cost way of reducing emissions of greenhouse gases by using free, available natural energies to heat and cool internal spaces and provide hot water – achieving the maximum effect in the time available to us – probably no more than 20 years?

Because our coal and gas fired electricity generators are highly polluting (producing about 80% of all emissions) and inefficient, (wasting about 70% of the energy generated and transmitted), the primary, urgent need is to reduce domestic consumption.

The problem is exacerbated by the fact that the use of electricity in Australian houses continues to rise by about 4-7% every year, but can be corrected by modifying our houses to use natural energies instead of electrical – discussed in papers on new houses and retro-fitting. Social and cultural changes needed to effect housing change are discussed in a third paper.

Solarisation - A 2003 proposal by Professor Andrew Blakers (ANU) was to form a commercial group “Solarisation P/L”, backed by the federal government. This would work by way of initial free advice and corrective activity, profits being derived from the resultant savings in recurrent costs. This would necessitate specialised trade training, and I see the formation of such a group as one of the very few ways of achieving the results we need in the time available to us.
Decisive action has, however, not been taken up by those who could do so, perhaps because of the lack of realisation of the need and the potential value.

2. New houses under design and construction – around 5%. While a relatively small proportion of the total source of greenhouse gas emissions, the design of new houses needs to be raised to a much more effective state of self-reliance by a thorough use of natural free energies. This must be achieved at the same time as the retrofitting program.

Current new housing is much the same as it has always been – conservative, old fashioned and ill-designed for the climate (particularly in the cool temperate regions of Australia, such as Canberra) – and the upsurge of public interest in the consequences of climate change must demand radical changes within the housing industry. To continue along the current path will almost certainly arouse scornful disbelief and anger from future generations at our belated unwillingness to take corrective action.

 

References

1. The other contributions by Derek Wrigley ito the Roundtable are on retrofitting, new houses, social and cultural issues to do with housing in Australia