double glazing or new boiler?

evei_2

A friend is buying a house that has 6 single glazed windows.

4 windows are about 1 metre square, 1 window 2 metres by 2 metres and 1 window 1 metre by 600mm.

So 8.6 square metres of windows.

All things being equal how much heat is lost through a single glazed window compared to a double glazed window with a 20mm gap?

The gas central heating boiler is also needing replaced. It works but it is old. She can live with not replacing the radiators.

She can only afford to do one or the other until a savings plan matures in 15 months time.

What would save the most money in the 15 months? New boiler or double glazing

Dognobs

Go for the windows and get a grant for a new boiler!

evei_2

Sorry should have mentioned this is in Scotland

Information for residents in Scotland:

The Energy Saving Scotland Boiler Scrappage Scheme for home owner-occupiers is now closed.

macman

Installing double glazing will not heat the house if the boiler is on it's last legs...

Cardew

Double glazing is one of the least cost-effective forms of insulation. Thick curtains, whilst not as effective, are certainly cheaper.

evei_2

Installing double glazing will not heat the house if the boiler is on it's last legs

It still works.

Anyway there other sources of heat if it does break down.

What would give the most savings, replacing the boiler or double glazing?

My friend wants to replace the windows first, you can see the windows, her OH wants to replace the boiler first, which you can't see. They have agreed that whatever saves the most money will be replaced first.

money is tight for them for the next 15 months. Also a new boiler works out costing less to buy than double glazing, my friend is looking for reasons to get the double glazing first, I think she is on a loser.

macman

I'm guessing that the replacement boiler will be half the cost or less of the double glazing? But it could take 10 years to recoup the cost of the new boiler in fuel savings.
Impossible to know which would save most.

tiddlyteri

I think double glazing curtains and put lots of layers on if that does not work :-)

evei_2

I found and filled out a survey online and it said that installing double glazing would save £25 a year in heating costs, my friend isn't happy about that. No double glazing for her.

Even I thought the savings would be greater considering how it is always one of the first things you do to save energy when improving a house.

They are going to stay in the house without double glazing and a new boiler and see what happens over the winter. After all the previous owners lived with them