Old sash windows

[LittleBoat1]

I've brought a double fronted 1900's brick build end terrace in a conservation area.. The sash windows are original, single glazed, most don't open.
Do I refurbish them?
Replace the sashes with double glazed ones?
Get secondary glazing?

I've just renovated five original, rotting Georgian sash windows in my listed house over the summer. When I say rotting that's what they actually were and mostly weren't opening properly
It was a lot of work, a family member is a carpenter, removed them all from inside. He then repaired the rot with some expensive filler stuff mostly, I sanded, removed old putty from the windows and used new where I had to then painted and then he put them back. He also had to repair rotting window ledges. We only had to replace one small piece of glass. After around two weeks he took them out again and I was able to paint the new putty, he then put them back properly( that's the very simple and short version!)
They look amazing, certainly not perfect but I'm so so pleased to have been able to save them, save myself thousands of pounds and also not have to apply for listed building consent to replace. I'm not allowed double glazing due to being listed but we stick up acrylic secondary glazing with magnetic strips through the winter which does make a difference. I strongly believe we should repair where we can
There are companies who will come and repair sash windows but I think you pay a great deal of money. I'm pretty sure a good carpenter or joiner could do the work ( don't know how much I'd want to do it in the winter though!)
If your windows are original and wood I'd look to repair

Do they have wibblywobbly glass?

Your windows are probably giving your house loads of its character, and should be carefully protected. A purist would repair these, replace rot (with wood), and get them functioning again. The sliding bits of the windows and sashes should not be painted, both top and bottom. (i can't remember, maybe they should be oiled).

I'm of the opinion that slim double glazing and draft proofing slides are a good upgrade. Often this requires new sashes, cords and weights. And costs lots. And will change appearance a little.

Leaving them painted shut isn't awful, if you can live with them shut and the single glazing. A big issue with these windows is rattling drafty sashes. It may not be too hard to break the paint seal and get them sliding again, but depends what else is wrong with them.

I do nearly everything on my house, but I wouldn't do sash windows. I'd find someone who has dedicated career to making and repairing historic windows and expect it's going to cost quite a lot.

We replaced half our sashes with new timber double glazed ones and refurbished the other half. Partly to keep the character (it’s the ones at the front we refurbished) and partly to save cost, as replacement definitely costs more, especially if the frame needs replacing too.

I have to say, a couple of years on and I wish we’d replaced the front ones as well. The new double glazed ones help SO much with sound and heat/cold insulation compared with the older ones, even after refurbishment. Although I suppose we do get ventilation via the older windows 😆

So if you can afford it I’d replace with timber double glazed in the same style. Not cheap mind.

I just recently had mine refurbished by a local guy who specialises in sash windows.
New cords, beading and draught excluder fitted within the beading, and new locks and handles.

£350 per window. Has made a big difference!

Deffo worth trying to repair - you can also get secondary glazing inside - a pane that meets in the middle and is less noticeable than you’d think - a lot of people in my building (also in a conservation area) have this.

@hesbeen2021 could you provide a link to the acrylic you use in winter? I have Victorian sash that also need a repair job but have yet to get round to it.

I’m in the same situation!! We’ve been looking at companies that restore the windows rather than replace, but it’s interesting that a PP said the restored ones aren’t as good with sound and heat insulation. Not sure what we’ll do!

The rules of the conservation zone might impact your options. I’m in Edinburgh and that is certainly the case here. We would have to refurbish or replace exactly like-for-like.

We replaced our 1880's original sashes with hardwood double glazed sashes made by a local joinery company. All the quirks of the mouldings (different in different rooms) were replicated.
You need to replace with hardwood because modern softwood doesn't have the longevity of Victorian pine.
It wasn't a cheap option ( we replaced 20windows) but we don't regret it at all.
When we moved in we draught proofed the windows as the wind literally whistled from back to front but it was still cold, they are huge expanses of glass and double glazing them made a huge difference.
Can't tell you exactly what the difference was on our bills as we also improved our insulation, boiler and have smart heating controls at around the same time so the combined effect was dramatic as was how much more comfortable the house was. They also now all open as they should which was great in the summer as you can use them to create air flow by opening them top and bottom.
The double glazing makes them heavier so the cast iron weights had to be replaced with lead but they move very smoothly.
Most people cannot tell the difference from the originals appearance (my conservation architect friend can but he does this for a living and conceded they were quite good).

could you provide a link to the acrylic you use in winter? I have Victorian sash that also need a repair job but have yet to get round to it.
Sorry no link as they were made for a couple of the houses in this terrace before I bought it. They're pretty ugly but basically see through acrylic which sticks to magnetic strips that you put on to the window frame. They do a really good job with sound proofing and heat retention but a bit of a faff when you want to open a window as you have to remove them each time ( you just sort of peel them off the magnetic strip) I bought new magnetic strip from Amazon I think

This shows how to install secondary acrylic

I found the acrylic sheets a bit ugly too. They are big and need storing somewhere in summer and get scratched up quickly. It's a no from me.

A (sash) window is the whole thing - all the wooden bits. Replacing or removing it would be a big deal. Removing a sash is a fairly normal part of maintenance. Sometimes they need replacing, and it isn't such a big deal.

Please accept my apologies if that was already clear. I'll go and be pedantic elsewhere.

They seem quite solid, heavily painted. The glass doesn't rattle.
What sort of paint did you use on the replacement windows?

Oooh thanks for this. Isn’t Jill fab?!

would you mind letting me know if you replaced your boxes or just the sliding sashes? We have to get all ours replaced in the house we bought a year ago and I am finding it a minefield. Everyone says something different in terms of whether we should just replace the sash or need a full box replacement and they are all quoting on different materials - softwood, hardwood, accoya etc. We have accepted that it’s going to be very pricey and are prioritising it over other more aesthetic updates I want to make because the house was flippin freezing this winter. I’ve basically narrowed it down to two companies - one quoting for full box rip out and one strongly recommending that we save our original boxes. Would be good to know some real world experience of either situation!

It probably depends a bit on the size of the window and their condition.
We replaced everything but that's mainly because ours are very large so once they became double glazed they became extremely heavy so needed completely new weights and when they opened them up the boxes weren't in the greatest shape.
Ours are Sapele replacing Victorian pine.
Victorian pine is very different to modern pine (much softer) so the equivalent now is to use a hardwood, Sapele is more cost effective than mahogany and has slightly better environmental credentials.

Ours have been in 9years now and had their 2nd coat of paint last autumn.
We had ours made by a local joiner that specialises in sashes and they made each one to the slightly quirky different internal mouldings. They are one of the best things we did for this house and although they weren't cheap I don't regret what we spent.

Thanks so much for the reply. It’s definitely in line with where my extensive research has taken me too. I couldn’t come to terms with the expense at the beginning because I wanted to do other works on the house but we have kind of come full circle and realised we just need to do this big messy job first. I think we also need full box replacement but for the inverse reason that a lot of our boxes are a bit too narrow to get a decent sized double glazed unit into them. Did you consider engineered softwood at all? Thanks again for taking the time to reply.

@KTMum2020
I did consider Accoya - I actually have it on my studio casement windows, but went with our joiners recommendation for Sapele.
They were real craftsmen and use it all the time (I'd seen their work before) so I went with their expertise. The price difference at that point wasn't massive - not sure what it is at the moment, knowing how much timber prices spiralled over the past 2 years.

@onmywayamarillo

Where are you / your sash window specialist based? if he covers London SW11 area, would you mind let me have his details please - we need to restore 2 sash windows. Thank you.

@bonechina05 sadly no where near you .

Whereabouts do you live? Are you happy to share his details?

Sorry to reawaken an old thread, but I'm in a similar position. I have two quotes, one for uPVC sashes, which are allowed in our area and the other for wood. The wood is redwood, which I believe is a soft wood - has anyone had this? Did it not last?

@minipie appreciate it’s an old thread, but can I ask something - did you replace the whole window including frame? And for the refurbished ones, did you add double glazing to them?

I’m asking as we’re in the process of refurbishing all of our sashes with double glazing retrofitted, we had the option of replacing the sashes (not the frames) for an extra £200 per window but decided we would prefer to keep the original wood, as we were assured the new sashes would make no difference from a thermal and sound insulation perspective.

so your post worried me that we’ve made the wrong decision, and that new sashes would have been a better choice… could you clarify what you had done?

So the windows at the back of the house were completely replaced - all wooden elements were taken out and replaced. New sash boxes, new sliding sash frames, new double glazing in the frames. New internal windowsills, architraves etc.

The ones at the front, nothing was replaced except some sash cords and locks. Just repaired, the weights rebalanced, and draughtproofing strips added.

For the front of the house we are now looking at a middle option of replacing the sash frames (the bits that slide) with new wooden sash frames and double glazing, but keeping the original sash boxes plus sills, architraves etc.

I haven’t heard of an option of keeping the original sash frames but putting double glazing in them. I think it wouldn’t be possible in our house as our sash frames are quite slim and wouldn’t hold the extra thickness/weight. However it may well be possible if your original frames are thicker and in good condition, still fit well and slide well etc. If so, it seems like a good option.

Ah ok thanks for clarifying!

were retrofitting the original sash with double glazing, ours are thick enough to hold a 14mm double glazing I think (or may be 16mm). Obviously won’t be as good as new windows but it’s about half of the price. They also remove the sash panels and repair them, add new draught proofing, new cords etc.

im hoping it will make a significant difference, our windows are huge and our house is very very cold

Hi all,

Please help. I am in Central London area and in need to have our sash windows repaired / refurbished. Any suggestion in experienced carpenter / sash window specialist repair would be most appreciated.

Thanks a lot.