Replacing windows

[Gardenbirdy]

All the double glazing in our house needs replacing. We can't afford to do the whole lot at the moment so are thinking of doing a couple of rooms at a time as we redecorate (bought the house 2 years ago and are gradually our way working through!)
I have literally no idea how much this would cost though - how much would a standard bedroom window cost on a 80s build house? Are we talking £100 or £500?
Obviously I know all houses are different but it would be useful to get a ballpark figure or hear from anyone who's done this. TIA!

[Testificateman]

It all depends on the spec and size of the window.

[PigletJohn]

do you mean the panels have gone misty, or is there something wrong with the frames and casements?

[Gardenbirdy]

The whole thing - frames and casements. We got away with just replacing the glass in the lounge as it'd gone misty but the rest need the full works. You can see the sealant around the edges is disintegrating on one of them. I've got a feeling it's the original double glazing from when the house was built.
I know quotes for doing an entire 3 bed house are from about £3000 upwards, I just wondered how this is roughly broken down.

[Testificateman]

Do you mean the silicone sealant around the frame of the window were it attaches to the wall?
If it's just that that's gone, you don't need to replace the frames, or the glass.
Tube of silicone, enough to do a couple of Windows, shouldn't cost more than a fiver.
Use a Stanley knife to cut the seal off and a wallpaper scraper to remove the rest.
After applying the seal, wet your finger and smooth out the sealant.

[Reality16]

I paid 6.5k for 7 windows and 2 doors last year

[unlucky83]

I understand why double glazing might need replacing - although it is something to carefully consider as apparently the energy savings aren't actually that great...unlikely you will get your money back in savings on your bills...
Depending on the problems I would get a DG repairman to look at them and see what they can do.
I have crap double glazing - good quality, but really badly fitted, the frames have warped. I've had new silicone seal and new gaskets (the rubber seals on the windows) but they are still draughty - I had a repair man telling me he wouldn't do them all as he was worried I'd be disappointed as several he couldn't really do anything with... I have silicone sealed some shut and fitted draught excluder tape to the rest...but they still need replacing. (I'm waiting till they start misting up to do them ...so far they haven't - I must be the only double glazing owner wishing their windows would mist up!)
Some older double glazing also has less of a gap between panes of glass so is less efficient (I don't have that problem) which could do with replacing ...or older aluminium frames that weren't insulated.
(Also mine have wooden panelling around them - used to cover up the cowboy job - there are huge gaps underneath it into the cavity -means there is a few mm of plywood between inside and outside - when we decorate I take it off and roughly fill it in before covering it back up ...but ideally you need them all plastered in properly. We had our house thermal imaged - the major heat loss is from the ones that haven't been done ...around the outside of the windows ....)
You can ask for quotes but doing a window at a time from what I know isn't the cheapest way of doing it ...for every window you have to pay for them to come out (travel costs), measure up, fit, scaffolding (if nec), insurance, guarantees, paperwork etc - it actually makes better sense to get them all replaced at once (and plastered in! one visit from a plasterer) - but then of course you are stuck with needing to re-decorate every room.
Also your new windows will have to 'match' your old ones... my neighbour was doing a window at a time over years (all white pvc) and they are slightly different as things change - not really really obvious, but you can tell if you look. And I can't remember the figures but he told me how much one cost once a few years ago and I remember I was shocked - thought it was expensive -compared to how much for a whole house.

[Gardenbirdy]

Thanks all, I had no idea you could just put on new sealant.
You're right Unlucky, it'll probably be better value to do them all in one go - the trouble is I want to redecorate the bedrooms this year and won't want the disruption of new windows afterwards!

[PigletJohn]

if there a gaps between frame and wall (often concealed by nailing on a bit of trim) I'd say it is more usual to inject expanding foam, then when it has set hard, knife and sand it smooth and you can use filler and pain, or new trim.

It is very sticky and expands more than you think, so if DIYing, practice in the garden first.

[unlucky83]

Piglet - I use expanding foam to bodge mine up...I (now) love expanding foam! Really useful stuff.
(Actually I also put it in the frame of the one of the really gappy ones I sealed up - then covered the set foam with silicone seal. The gap between window opening and frame was a cm wide - too wide for silicone alone.)

I have cavity walls (not filled - don't think they are suitable, are quite exposed) and I might be wrong, over reacting, but I always worry about it bridging the cavity - try and just use an amount that is about the width of the brick in the inner layer.
And agree about it being sticky and nasty - I have a long story about the first time I used it...on a Christmas eve, not reading the instructions - a real disaster- no nail varnish remover to get it off my hands or even talc to stop my fingers sticking together - I ended up with flour covered lumps on my hands ...
So practice first , read the instructions and have acetone/nail varnish remover (or foam gun cleaner) available to clean up before it sets.
You can get something called foam eater to get rid of the set stuff on some surfaces -but easier to get rid of it before it sets.
Actually I have a foam gun now, rather than use a DIY can, cos you can control it better...