“What is the one thing everyone should do?” is the question I get asked most often by newspapers, interviewers and the like. What they want are some pearls of wisdom on solar panels or heat pumps or some such. But the, perhaps disappointing, answer is draught proofing.

In an older property draughts will account for at least 10 per cent of the heat loss. A typical Victorian three-bedroom semi will have a heat load in the region of 20,000kWh to 30,000kWh, so a 10 per cent saving equates to around £100 per year. If the house has unused open fireplaces, the heat loss though draughts can be over 25 per cent, and now we are talking about a lot of money.

The thing with draughts is that they are easy, and cheap, to fix but we tend to learn to live with them. There are lots of products in your local DIY shed for sealing round windows and doors; good old mastic will do the job at the junction of floor and walls, and even gaps between floor boards. And don’t forget penetrations through walls for pipes and cables. Chimney flues can be bricked up or there is a handy balloon-type thing called a Sempaflu that will do the job.

A couple of notes of caution; beware air-bricks. Make sure they can still circulate air where it is needed, typically to the ground floor joists. No air means wet or dry-rot getting established. And if you are sealing the chimney you will need to seal it at the top as well as the bottom. Sealing the bottom will still allow rainwater into the top, with consequent damp problems now that the flow of air that used to dry it has been blocked.

Draught proofing is not sexy and will not make a good topic of conversation in saloon bar of the Red Lion on a Sunday afternoon. But it is without question the single most effective means of improving energy efficiency. £200 worth of draught proofing will save more energy than a £5,000 solar panel and twice as much energy as swapping all your light bulbs to low energy CFL’s.

photo copyright Clayton Hansen, iStockphoto

About the author: Tim Pullen is eco-editor for Homebuilding & Renovating magazine, author of Simply Sustainable Homes and founder of sustainable property consultancy WeatherWorks.

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