Double-glazing all the windows in a house will cost £4000. It will mean a yearly saving of £200 on energy bills. What is the payback time in years?
Answers
Answer: Replacing your windows with double glazing to just save money does not actually make a lot of sense. You will reduce heat flow through you windows by at least a half assuming this is the only insulation measure installed in your house you should reduce you overall energy bill by between 5% and 10%
.For the smaller 3 bed house assuming you save the maximum 10% of your heating costs you should save £70 each year if you are gas heated and if it cost about £5000 to install the windows the investment will payback in about 70 years.
The payback for this investment is long! If however you are replacing old windows and generally upgrading your property it is very well worth doing, or if you are just sick of the constant drafts next to your old windows. Also a pure pay back figure for double glazing does not account for the increased value of your property, so the figures in the table do perhaps present a more negative picture than double glazing deserve, however the best case scenario of 10% savings is presented in the tables together with the associated
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