So; our windows are single-glazed wood frames affairs, with two sash windows, the rest with opening panes. They aren’t very heat efficient, and don’t block out noise very well. So we’d like to replace them with double glazed units.

What are our options? Adapt existing frames (swap inner frames for DG units), or change the whole lot? We’d prefer wood frames; UPVC won’t be going in our home.

How easy would it be to DIY some frames?

It’s not too hard to replace a single pane with a DG unit that you’ve got made up by a local glazier, as long as there’s enough depth in the rebate. You need to use a low-modulus sealant to seat the units and then if you use putty, make sure there’s no direct contact between the putty and the mastic that seals the units. Get advice from the manufacturer about dimensions; I did two arched windows and the units were a tight fit so I ended up grinding all the dried putty and some wood out of the rebates with my angle grinder, which made a lot of dust.

The easier alternative, as you’ve written, is to get some inner frames made up with DG units and simply swop them over. This might enable you to have a wider separation inside the units. With sash windows you might need to increase the weights a bit to counter-balance the extra weight of glass.

Great stuff globaliti, thanks.

I’m leaning towards the DIY option, although I am under no illusion that it will be an easy task. I have made a small window frame and glazed it myself, and that was pretty simple really, so I’d like to consider the DIY route before spending thousands on a professional job. It’s not the money saving that we’re bothered about (negligible over time), it’s the heat loss and noise insulation that’s of greater concern.

Would I need to seal the panes in any way within the frames, to prevent moisture/condensation from formin between the panes? And the current frames don’t sit flush to the outer frames, meaning there’s a slight draught on some windows. What sort of insulatory methods are there?

I have uPVC double glazed sash windows and they are great.

They were put in 12 years ago and have been completely faultless, even tilt in so you can wash them from the inside (handy for upstairs windows).

New wall by brf, on Flickr

As I said, UPVC isn’t going in our home. Aluminium at a push, but we’d prefer to stick with wood, preferably even using the existing main frames if possible.

Was hoping for a few more responses, obviously double glazing really is a dull subject!

Of course, we’ve waited for the cold(er) weather to arrive before thinking about it. But is it better to have it done at any particular time of year (thinking of materials expanding/contracting etc)?

An architect friend recommends secondary glazing, but I think that will be an expensive and awkward solution really.

As close to the existing wood frames as possible is the ideal. Anyone done their own frames? Experiences? Pictures even?

We had sash windows in our house and just changed them in February to triple glazed as it was about £100 more than double glazed for the whole lot. Pondered on it for ages about putting plastic in but at the end of the day wood is just so expensive and pointless if you put softwood in as you just have to constantly maintain it. We used a firm in Bristol that we used years ago after much hunting around as they were the only ones that would put wood surrounds on the inside and not plastic. Basically they ripped everything out right back to the stone and then installed the windows and internally put in wooden sills and surrounds and edging.

Very pleased as the house is loads warmer and the reduction n external sound is just massive!!

I came to the conclusion that there are far to many other things in life to do and worry about than windows so plumped for white UPVC that I will not have to do anything with. Initially I wanted hardwood sash but now I am 100% happy with what we went for.

Basically they ripped everything out right back to the stone and then installed the windows and internally put in wooden sills and surrounds and edging.

Very pleased as the house is loads warmer and the reduction n external sound is just massive!!

Yep, very happy with the PVC sash, excellent noise reduction, insulation and zero maintenance.

If you prefer the look of wooden sashes to UPVC then all is not lost. I have put a fair bit of effort and time into getting my wooden sashes sorted out this leaflet from english heritage details performance increases.
Mine are pretty good now..

This thread was made for TJ 🙁

My abhorrence of UPVC is based on the fact that almost all UPVC window systems I’ve experienced are either poorly manufactured, or end up disintegrating after a relatively short time (as little as 3 years even). The wood frames in our house are several decades old. I don’t know about current materials I admit, but I’ve discounted the use of UPVC.

Using wood would be in keeping with the style and period of the house, and offers the possibility of the DIY route. Plus, we’d probably be able to use recycled wood and even glass, which would be ideal.

Change the lot for new frames and triple glazed windows – anything else is a compromise.

I make quite a few hardwood sash and openers, all double glazed (even the listed buildings which use a slimlight glass).
Don’t re-use your glass, it’s the cheap bit and without the argon (or preferably krypton) gas filling, the systems will not work as well, and if the gas has escaped, moisture will get in and then you’ve got condensation inside your pains…
If the rebates are not big enough for standard double glazed units, then check out slimlight, and if still not big enough, new windows time!
Secondary glazing is good for noise reduction, but poor for heat loss.
I will say that the modern upvc’s are very, very good and I’d be quite likely to have them in my current victorian terrace, except that I can make hardwood ones for a cheaper price!