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Extend and save energy!

Updated: Mar 23, 2023

Did you know that extending your house and making it bigger could actually reduce your fuel bills- drastically?

Yes, this is absolutely true. If your house is a few decades old when insulation wasn't a priority your house will be emitting much more heat than a modern home. Let's move I hear you say but wait, there are things we can do to reduce your heating bills. One of the most drastic is also one of the most cost-effective and that is to extend your home. Of course, if you extend, and you do it wisely, you will gain more space, add value to your house and most likely, reduce your heat emission. Let me explain in a very crude way how this works.

External cavity walls built in the early 1980s emitted over three times the heat a modern similar wall does. Go back to the 1960s and this figure is over 6 times but let's work on the basis of the 1980s house. This means that an extension of 6m square, with a perimeter of 18m, will have the equivalent heat loss of the 6 metre long wall of the existing house that has now been enclosed by the new extension. Now, it's not the whole story because you will have more roof and floor area emitting heat and so we need to make allowance for this but we now have to insulate floors, whereas 1980s houses had no floor insulation and a puny amount of roof insulation. So that means that the heat loss for the new floor and roof areas will be comparatively small. And of course, the real game changer is in modern windows and glazing. Modern windows, with triple glazing, lose about a quarter of the heat that a 1980s single glazed window would lose, and windows are still the weakest link in the chain. So by installing triple glazed windows in your extension and making allowance for the heat lost in the old windows in the existing wall, you will more than save the heat lost in the extra roof and floor.

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