Is It Worth It? - Replacing 30+ Years Old Double Glazing

lovelifer

Hello

I've googled but haven't found much about this issue so thought I'd ask here.

i have 10 windows in my 1930s house and think they're from the 90s (you couldn't climb out of them in the event of fire). One large one is blown, the rest OK I think. I've had 2 quotes from local businesses- £5000 for upvc; £12000 for wood.

My question is- are modern window units more economical? Or is it neither here nor there? The current ones look OK.

Any thoughts welcome.

Grenage

Are they more efficient, yes.  Will you save money overall - certainly not.

Ectophile

Any decent glazier will be able to replace a blown window panel.

New windows will be more efficient.  But unless there's something wrong with the old windows, they won't be that much more efficient.  £5000 buys you a lot of heating.

Do you really have no windows that you could escape through if there was a fire?  If it's a 2 or 3 storey house, I would expect at least some windows to be openable so that the fire brigade can rescue you.

EssexExile

Replacing the blown unit will probably cost a (very) few hundred.

ThisIsWeird

As said by others, provided the seals are in good order - Ie the openers are draughtproof when shut - then your DG units will already be doing a cracking job. I bet the units are nicely thick too? (I have older ones than you )
Yes, modern units will definitely have the edge over them, but they won't be transformative. Say replacing them all will save you, ooh, £100 in energy costs a year (no idea if that's realistic), it would take you between 50 and 120 years to recoup your outlay
Even the 'blown' unit which is misty inside will only lose a tiny amount of insulating effectiveness - it is almost entirely just a cosmetic issue. If you get any condensation forming on the panes on cold nights, just compare the amount on an ok glazing unit with the blown one - I bet there won't be any difference.
Old double glazing is a bit like an old boiler - keep it going for as long as you can

FreeBear

*This house had double glazing fitted around 1976 (if I remember correctly). Wooden frames with an aluminium insert to take 14mm thick sealed units. The bedroom windows were badly installed, and there was always a cold draught coming in around the edges. Over time, the wood had started to rot due to a lack of maintenance. For me, it was a well worthwhile investment having new windows that fitted properly. Modern sealed units are much more thermally efficient, and being uPVC frames, I'll never have to bother painting them. Not saving a huge amount on energy, so I'm unlikely to recover the cost through savings. But the quality of life has improved dramatically, which is something that is difficult to put a value on.

A 1990s window is probably going to be 24mm thick sealed units. If your frames are in good condition, then just replacing the glass would be fairly cheap and cut your heating bill a little. You would also need to check the state of the seals and hinges - If these are wearing out, they should be replaced IF you can find suitable replacements. One of the issues I had with my old windows were the hinges needed replacing, but could not find any new replacements.

victor2

We had 30 year old UPVC DG windows in a dormer and a few had blown,plus one hinge had broken. Otherwise they looked OK. Got a local DG fitter to replace the hinge and all 8 panels for £1K. As the old panels were removed I cleaned the frames with UPVC cleaner.
Much cheaper than replacing the lot.

lovelifer

Brilliant , thanks all. I got caught up thinking it'd be a good move aesthetically as well as economically but you've helped me see I won't get 5k worth of extra attractiveness. 

In terms of escape there are 2 i could climb out of but its not a big house so this is theoretical only I think.

A lock has failed but I can fix it or get it done for not much money i think.

Thanks again, this has really helped me think it through properly.

FreeBear

lovelifer said:

Brilliant , thanks all. I got caught up thinking it'd be a good move aesthetically as well as economically but you've helped me see I won't get 5k worth of extra attractiveness.

If you were to replace all the windows, under the latest Building Regulations, you'd also be required to have "background ventilation" added. Most installers take this to mean trickle vents - I dislike the darned things and think there are better ways of providing ventilation such as MVHR or PIV. However, the regs do provide a route to avoiding trickle vents. If the windows face a busy main road or another source of constant loud noise (e.g. a busy airport), trickle vents can be omitted on those windows. Or if you replace less than 30% of the windows at a time, you don't have to have trickle vents fitted unless the old windows had them.

lovelifer

This thread gave me a kick up the backside- tackled the non locking window and it's working again- thanks to a clean, wd40 and some fiddling.