Bi-glass sash window replacements anyone???

[Spockster]

We are looking at renovating our sash windows and wonder if anyone has had the glass replaced with double glazed bi-glass? Would love to know if it works; the gapm between panes is apparently only 5mm, and I don't know if that is enough...?

DP makes and fits bespoke hard wood windows, he would say 5mm is too small as the bigger the gap the better the insulation. I've just checked mine that he did and the gap is at least 1.5cm.
I'm not sure what bi-glass is though, we have Pilkington K glass.

Thanks for that; it is a method of replacing the glass in the window with double glazed glass, without replacing the window itself; they come along & take out the old and put in thr new. The problem is, old sash windows can't take anything with a bigger gap. Apparently. I don't know what to believe!!! Our windows seem in quite good nick but are draughty and we get alot of traffic noise, so I am hoping it might help. I am going to try good old draught-proofing tape first though... .

I don't know the answer to this but the people you might want to talk to are The Sash Window Draughtproofing Co. www.sashwindowco.co.uk/sashwindow_manufacture.htm. They may not be near you (they are near Bristol) but could probably offer advice. They make new double glazed sash windows, but also refurbish/repair and I think would probably give you a straight answer, rather than just say 'can't be done'. He's certainly a stickler for getting it right in terms of aesthetics. We have just had some new windows put in, and used them (they aren't cheap! but who is?) because they were the only ones who were prepared to do very narrow glazing bars, like original sash windows, but with double glazing. Everyone else we spoke to just sucked through their teeth (you know what I mean!)and said it couldn't be done...

Fab thanks, I will get in touch; I want to get at least one more quote, anyway (from someone who won't try to sell me uPVC...even my Dad has tried!)

From my experience typing up dps quotes etc its probably cheaper or at least more effective to have new windows and frames made than just replacing the glass - especially if the double glazed units going in don't have a big enough gap to be effective against heat loss/traffic noise.

Just replacing the window sashes is going to be about £1000 per window (for the small ones) and still won't be able to take a thicker gap; to replace the box frames as well would be too much, as the whole house neeeds doing. Sigh.

Have to say I agree with FTJB - I'd be inclined to get quotes for replacements as well as refurbs. From the figures you are quoting you might find there is very little in it (bizarre though that might sound).

We're having our sash windows overhauled in the new year. Our carpenter said that the rebate on them wasn't deep enough to replace with double-glazed panels and all the windows would require replacing if that's what we wanted to do. (I declined!)

PLEASE let me know how it goes; I am still wondering if an overhaul and some really good draughtproofing might be adequate...

Are you in a conservation area and how keen are you to have actual operating sash windows in? DP did ones for my house (that would have had sash windows in donkeys years ago but had yuk upvc when I moved in) were a mock sash - look exactly sash when closed but the top bit opens out like a normal top-hinged window. That way you don't need all the box frames as well and can get the gap between panes as wide as you like.
Still not cheap but def better than replacing working sash and box frames.
Where do you live i can send him round to quote
Where are you getting the quotes from though, DP is a carpenter - he just makes the frames and orders double glazed units to suit them from a bog standard glass place. I suspect that a 'window specialist' company will charge much more than if you can find a local skilled carpenter. And the window company will only use their own carpenters and double glazed units but charge a premium because sash windows are not standard anymore.

We are not in a conservation area or listed, but we really like the sash windows and I would be loathe to replace them with anything other than replicas. And it does seem to be cheaper to replace just the sashes and keep the box frames. But you are right it is very expensive to use the window companies, but it is hard to find a local company to trust!
We are in South Bucks; would love a recommendation if anyone knows a local carpenter...

I can just see you like my gran used to be, sitting outside on the window ledge with the sash window pulled down to wedge her legs, while she cleaned the outside of her windows!
I do understand wanting to keep them they are lovely to have - but the box parts had been filled in by previous owners of my house and we live in a cheap-ish housing area of Lancashire - dp said if I replaced all the windows with proper sashes my windows would be worth more than the house! As it is I'm the only person in the street with wooden window frames...

we had ours done by a local joinery company
(not local to you im afraid)

we have double glazing in new wood sash windows

they are large and cost 1000 each.

they fit well and there are no draughts but i must say the sound proofing is not perfect - there is some muffling but not what we hoped for - if sound is a real issue triple glazing is probably the better option

everest do sash style windows that slide up and down which are not wood but are covered in something plasticy to protect from elements and they are truly soundproof but cost a fortune

if you get new ones make sure you have a contract and check who paints them, fits them/makes good the plaster around them

We got quotes in my last house for replacing the sash windows. Definitely get quotes from 'joinery manufacturers' as listed in Yellow Pages. Much, much cheaper than window companies or sash window specialists

Fab, thanks everyone. I'm off to B&Q to buy some draughtproofing strips to get us through the winter!