Anyone had slimline double glazing fitted in old single glazed sash?

[Whatsthestoryboringglory]

Morning all. We live in an old Victorian semi that has been a bit neglected before we bought it. The sash windows are wooden single glazed, and need attention. They rattle, have no draught proofing and we can see daylight between the two sashes. The frames need some TLC but we think they are essentially sound.

I’ve been looking at replacing them all with wooden double glazed sash, but it’s pretty expensive. Someone local has suggested we get slimline double glazing in the existing frames, using a company that will refurb and fully draught proof at the same time.

Does anyone here have experience of this? Wondering if it’s cost effective or if we would end up spending more?

We live in a conservation area, and money is tight so would go for most cost effective. Especially as they leak like a sieve currently and with the utility bill increases!

Personally I'd go for the best insulated possible ie fully double glazed wooden sash replacements. Looks so much nicer and definitely makes a huge difference in draughts, might cost a bit more but I think will work best at reducing costs overall.
You'll need to check the requirements of the conservation area legislation though - see what's allowed.

Thanks, that’s what my initial thought was but have no experience of refurbed windows with slimline double glazing retrofitted so wondered if that might be just as good. It’s an expensive minefield!

It won't meet current building regs.
I did this and it was picked up by the building inspector when he came to check something else. I hadn't realised they didn't meet regulations. As it happened I did a lot of other measures (it was an 1860 detached house with no insulation) and properly double glazed the back (replacing the box sashes completely was about £1000/window, the ones in front with slim double glazing to existing boxes were less than half that) so I got away with it, and it wouldn't put me off purchasing a house, but some people (or their solicitor) will be funny about it.

We had it done with ours and it has made a difference. The biggest difference was the ventrolla system though which is brushes etc which are fitted where the widow's meet to draft proof them. Made a big difference. We had another set replaced with new but they put those annoying springs in instead of using the sash weights and they don't open or close easily any more.
I actually bought my own double glazed panel and put it into the back door by myself and it is pretty easy to do.

If it isn't warm enough you could always put secondary glazinv up in the winter.

I am always a bit confused by the building regs thing as no old buildings will meet modern regulations as they didn't exist when they were built and quite often it isn't possible to change them to meet modern regulations although I guess that windows could be an exception.

I'm interested in this as we are in the process of buying an Edwardiam detached house with single glazed sash windows. It's a house where every room is on a corner so has two windows. I'd assumed it would cost at least £20k to replace them all, so wondered if there were alternative options

Did he say why they didn’t meet current building regs @easyday

We did this - victorian 5-bed townhouse, cost about £20k. Lots warmer. And also v good for sound insulation (we hadn't planned it for that reason, but as a side effect it made the house feel much cosier/haven-like)

Ours all had to be ok'd by the listed building people and was fine. I don't think building regs came in to it (from my memory).

I've had this done in a 4 bed, 3 storey victorian semi, cost about £14k 5 years ago. They keep the draughts out and the house is much warmer. I had the original windows fitted with slim double glazing. They look really good, people sometimes knock on my door just to tell me that they love the windows!

Secondary glazing gives much better thermal and sound properties than replacement double glazed or refurbished originals. Plus the original glass/reflection is so important to the character of the house and is almost irreplaceable - only possibly with heritage glass which is prohibitively expensive. The timber used in modern windows will never last like the originals either.

Thanks everyone, lots of food for thought here. I hadn’t taken in to consideration any issues with buildings regs. Might need to have a chat with someone about that 🤔