Page 3627 - Week 08 - Thursday, 19 August 2010
Next page . . . . Previous page . . . . Speeches . . . . Contents . . . . Debates(HTML) . . . . PDF . . . . Video
Secondly, energy efficiency ratings should, we believe, be published on a whole-house basis rather than on a per-square-metre basis. Most people seeing the energy efficiency rating do not realise that it is a rating which relates to how much energy will be required to heat or cool to a comfortable level each square metre of the house. What this means is that a smaller house that happens to have a lower energy efficiency rating could in fact end up using less energy than a larger house which has a higher and better energy efficiency rating.
We would like to see both the current energy efficiency rating published and a rating for whole-of-house. It is a simple multiplication exercise to do it. There is no additional software or anything required. We would like to see them both published, as is the case for most appliances. Appliances will give you a star rating and they will say how many kilowatt hours you would expect to use over a year. I think at present it is often confusing for people when they move into a higher-star-rated house which also happens to be a lot bigger. They find their energy bills go up because they are simply heating or cooling a lot more than they would in the past.
Of course, we do recognise that for house operation one of the most significant issues is how you use your house for energy efficiency. You can use a lot of energy even in a well-designed house if you operate it poorly. Conversely, many people in not-so-well-designed houses do not use an excessive amount of energy because they operate their houses very well. Nonetheless, I think it would be useful for consumers to have that additional number.
Thirdly, I would like to note that the current energy efficiency rating only discloses the thermal performance of the building envelope, the building shell itself. It does not consider the appliances at all. The energy used for space and water heating represents a significant proportion of household energy consumption. We debated this again last year with the Greens’ hot-water bill. We think that where we are talking about long-living appliances which are actually fixed to the building, they should be disclosed as part of the energy efficiency rating as a separate item so that people, when they buy a building, can say, “I have got a great hot water,” or “I have got a hot-water service which is going to be really, really expensive to run.” They should be able to say that their heating service is going to be energy efficient or that it is provided by a couple of bar radiators and they may have problems.
We think this should be a separate item from general energy efficiency because we would not want to have the situation that a high performance solar hot-water system was used to disguise poor building design. We would also suggest that the water performance of the house could usefully be disclosed.
Fourthly, how energy efficiency ratings are worked is based on thermal modelling. The models use weather records from the past for their simulations. However, we all know that the weather is changing rapidly. When we are designing houses we need to design them for the future, not the past. That, of course, is when they are going to be used. We need to start looking at doing the simulations on the basis of the reasonably expected and predicted weather for the future.
Next page . . . . Previous page . . . . Speeches . . . . Contents . . . . Debates(HTML) . . . . PDF . . . . Video