Matilda Lee: How big are the energy costs of our homes?
Anne Power: Massive, in three different ways. One, the land they sit on and the roads that they require cause floods, affect biodiversity and use up land needed as a sink for our pollution.
Second, the energy required to build homes, from brick making to quarrying slate and creating steel girders, is huge.
Third, they leak out heat through poor insulation and draughts - which is where we could make an 80 per cent saving.
The more we preserve older homes, the more we encourage greater density, and the less we encourage sprawl, green field building and wider environmental damage.
ML: What is your recipe for the 80 per cent energy savings you mention?
AP: I use the analogy of the tea pot. You make very hot tea in it, and within 15 to 20 minutes your tea isn't very hot anymore. The houses we live in are exactly like that. Within a short time, most of the heat pumping through them has escaped.
Very alarmingly 35 per cent escapes through the walls, 15 per cent through the floors and 15 per cent escapes through doors. And roofs leak 25 per cent! If you put a tea cosy on a tea pot it will double the time the tea stays warm. Multiply up the amount of insulation you put in a building: you save energy.
Another aspect of the tea cosy is to stop draughts of cool air chilling your teapot. Draughts are small spaces that have air push through them and allow an accelerated flow of air. Even without the air being very cold, draughts make your house cold. The German approach has been very inspiring in blocking up all air gaps and wrapping buildings in thick layers of insulation.
ML: What is it about the German approach?
AP: First they did a big trial from 2003-7 across hundreds of properties and showed that they could get energy down by 80 per cent. Secondly, it was so persuasive that the German government adopted it nationally and decided to retrofit all pre-1983 properties by 2020. They do about 600,000 properties a year.
Third, they have an investment bank - the Kreditanstallt für Wiederaufban (KfW) - an investment bank for reinvestment in property created after the Second World War and owned by the government, which provides money for these programmes. It would make a huge difference if we had something like that here.
Four, all of this is job intensive. New-build houses are 70 per cent materials, 30 per cent labour. Renovation is 70 per cent labour, 30 per cent materials. We have over a hundred thousand small builders. Poorer neighbourhoods, which need a lot of retrofitting, stand to benefit most from the job creation. It's a win-win approach - more jobs, warmer homes, cheaper bills, combating climate change.
ML: Don't the high upfront costs hamper the incentives homeowners have to make homes more energy efficient?
AP: For what it costs you to put in a new kitchen - which apparently people seem to do around every five years - and a new bathroom, you've insulated your house. It really isn't true that most people who own a house don't have the money to insulate. They spend money on other things. So, it's how you persuade the average homeowner to give this priority.
ML: So, this is down to the individual then?
AP: No, because in Germany there was a high profile national campaign, big publicity and promotions and big financial incentives to do it. This included feed-in tariffs and low-interest loans. One of the things the UK Government has decided to do is to create Pay as you Save investment. At the moment, it's only five pilot schemes. The ambition is to insulate homes through the Heating and Energy Management Strategy.
This was launched yesterday, and Ed Miliband has declared that this should be a very ambitious programme. It is strongly linked to the feed-in tariff and the Renewable Heat Incentive (RHI). Warm Homes, Greener homes came out on 2nd March.
ML: Do you think the feed-in tariff is too low?
AP: From what I've read and the people I've talked to about the cost balances of the investment versus the return, all agree that this is really good news. You receive £400 a year, and create your own energy supply at a massively reduced price. It didn't strike me as a bad offer!
ML: There were 130,000 new homes completed last year, with building regulations getting more and more strict. In your view, though, the real issue is the need to retrofit the existing home base?
AP: We have 24 million existing homes, pretty much all of them, bar about five million, need to be retrofitted. The average SAP rating [the Government's Standard Assessment Procedure for energy rating of dwellings] for modern, recently built homes is 60 and it should be 80. The overall SAP average is 51-53. We are way below where we should be.
ML: Aside from cost, what other barriers are there to energy efficiency?
AP: Loads. It's very difficult to do. The know-how is very scattergun. But there are lots of things that are easy, such as putting cling film over your windows, door stoppers at your doors and draught proofing around windows and doors. If you've got a basement or ground floor with carpet, you can put lots of cardboard boxes or newspapers under the carpet! You can thermally line your curtains. You can definitely make a 25 per cent gain with cheap and simple actions.
ML: What are the best alternative energy sources in urban areas?
AP: If you've got a south, south west or south east facing roof, then solar water heaters and solar PV are definitely worth it. With the feed in tariff, the gains from Solar PV are very significant. Air source heat pumps and heat exchangers are both useful and relatively easy to install.
ML: How do we reach households with residents who might be older, have disabilities or be socially disadvantaged?
AP: Interestingly, it is more straightforward than with the general population. Social landlords are taking the lead, experimenting with delivering energy savings through the Carbon Emissions Reduction Target - an obligation to reinvest in energy saving. Warm Front and Warm Zone investments seem to pick up a lot of low income people and do work to make homes less wasteful. More needs to be done to reassure and ‘hand hold' vulnerable people through the process.
ML: How can the Government and the media ‘sell' the idea of energy efficiency better?
AP: People are much more energy conscious than they used to be, and the idea that you can get something for nothing through energy saving really appeals. If you get into it, it becomes quite compelling. The crucial thing is to get people into it, which is where I think things like the Transition Movement, the 10:10 campaign and government incentives are terribly helpful.
Matilda Lee is the Ecologist's Community Affairs Editor
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