Double glazing in a listed building?

[dhutch]

hotchy said:

One near me just went ahead and got all new windows double glazed. Lasted 6 months and all had to be put back to original. The rest of the streets just went for secondary glazing inside.

Had to be put back to original, because they were made to? Where the windows of the correct and matching style, just with a second sheet of glass, or did they swap period windows for uPVC monsters?

You can install 'slimline' double glazing into wooden windows, or even retro fit it to old frames, in a way which is almost indistinguishable. Before the rash of uPVC it was called 'double glazing' but unless you are within 18 inches and either squint or put something against it, you can't tell.

For me this is a no-brainer, in terms of what I would allow as conservation officer, and in terms of reducing condensation issues and the like.
Sadly common sense appears to be fairly randomly places and at times a bit rare within these circles.

Obviously in terms of heat lost, while comfort it part of it, double glazing rarely pays back within its lifetime as I understand it, and you are likely better off spending the money on draft proofing!


Daniel

[FlipFlopGriff]

Do you have any old glass in the frames, ie not flat, but has imperfections and maybe bubbles? If so I'd refurbish what you have and secondary glaze. Once the old glass is gone its gone forever.
Sound like Drew Pritchard there.
FFG

[bennno]

FlipFlopGriff said:

Do you have any old glass in the frames, ie not flat, but has imperfections and maybe bubbles? If so I'd refurbish what you have and secondary glaze. Once the old glass is gone its gone forever.
Sound like Drew Pritchard there.
FFG

Thats very accurate, we had a lot of rotten lower sash windows. The sashes got replaced but old glass wasn’t transplanted due to its fragility - big loss as it has so much character.

[FlipFlopGriff]

bennno said:

Thats very accurate, we had a lot of rotten lower sash windows. The sashes got replaced but old glass wasn’t transplanted due to its fragility - big loss as it has so much character.

I've got a couple of old windows where the putty has all split and come away so I need to replace it and I'm dreading it as the glass is so fragile. We've got a guy locally who restores old windows, including stained, and he has supplied replacement windows, including oak frames, wrought iron casements, leaded lights with handblown glass (to suit the period) and he is English Heritage approved. Not cheap but pretty good value for what you get and they look right.
From this, 1980 Magnet window:

To this (best pic I have but one side still unglazed):

FFG

[dhutch]

Looks a loverly window, although could you not just have raked out the putty and replaced that?

[FlipFlopGriff]

dhutch said:

Looks a loverly window, although could you not just have raked out the putty and replaced that?

Different window. The top one is a 1980's Magnet window with flat glass and stuck on lead. The one in now is oak framed, wrought casement opener, and hand blown glass with imperfections - the glass guy advised on what type of glass based on the building age.
We also had a round window with radial window bar done which was literally a piece of glass with silicon raidal painted black, so from the outside it looked original but wasn't. that cost us £600! and its only around 2 foot diameter and a fixed pane - a lot of cost in the oak frame apparently.
FFG .

[bennno]

FlipFlopGriff said:

bennno said:

Thats very accurate, we had a lot of rotten lower sash windows. The sashes got replaced but old glass wasn’t transplanted due to its fragility - big loss as it has so much character.

I've got a couple of old windows where the putty has all split and come away so I need to replace it and I'm dreading it as the glass is so fragile. We've got a guy locally who restores old windows, including stained, and he has supplied replacement windows, including oak frames, wrought iron casements, leaded lights with handblown glass (to suit the period) and he is English Heritage approved. Not cheap but pretty good value for what you get and they look right.
From this, 1980 Magnet window:

To this (best pic I have but one side still unglazed):

FFG

That’s a nice bit of work, ours everso slightly larger.... and a bit more than £600....

[Amateurish]

Thanks for all the advice so far, I will contact our local CO to discuss.

As for the existing windows, they are 20th-century replacements, single glazed and set within openings with an original shallow arched head, with various masonry and render used as infill between the rectangular frames and the masonry. Presumably installed in the 70s when the property underwent significant renovations.

[Elderly]

FlipFlopGriff said:

...... and hand blown glass with imperfections - the glass guy advised on what type of glass based on the building age.
.

Our CO said that it was important that you could tell that any replacement could not be mistaken for 'original'.

I pointed out that the house was Listed - i.e. there was a list of work done.
The response was " What if the list gets destroyed?".

I agreed and said that I should therefore put in a white upvc triple glazed window as it could never be mistaken for 'original' ....
..... that went down well

[Equus]

Elderly said:

I pointed out that the house was Listed - i.e. there was a list of work done.

That isn't the meaning of 'listing'. The actual description of the building given on the statutory listing is quite brief.

You could potentially try to piece together the recent (post 1948) architectural history of the building from documentation on each individual LBC application held by the Local Authority, but that is also problematical and again the information may not be all that comprehensive (or reliable).

[FlipFlopGriff]

Elderly said:

Our CO said that it was important that you could tell that any replacement could not be mistaken for 'original'.

I pointed out that the house was Listed - i.e. there was a list of work done.
The response was " What if the list gets destroyed?".

I agreed and said that I should therefore put in a white upvc triple glazed window as it could never be mistaken for 'original' ....
..... that went down well

And thats where the advice isn't consistent. I'd argue with ours to replace with something in keeping. I have another matching Magnet window upstairs on the opposite gable which I want to replace with the same as the one already fitted. Most of ours are old, not sure if original, and the "modern" windows look really out of place in the building. We're going to get some security bars added internally to the downstairs windows to increase security as single glazed, fairly easy to access, isn;t the best these days - would have been fine 300 years ago when you could leave everything open and unlocked without any fear of being robbed. One or 2 of the windows have the bars but not all of them.
FFG

[nikaiyo2]

Amateurish said:

Thanks for all the advice so far, I will contact our local CO to discuss.

As for the existing windows, they are 20th-century replacements, single glazed and set within openings with an original shallow arched head, with various masonry and render used as infill between the rectangular frames and the masonry. Presumably installed in the 70s when the property underwent significant renovations.

It might be worth giving https://theheritagewindowcompany.co.uk/ a try they do a very slim frame that can be glazed directly into stone/ masonry.

[FlipFlopGriff]

Amateurish said:

Thanks for all the advice so far, I will contact our local CO to discuss.

As for the existing windows, they are 20th-century replacements, single glazed and set within openings with an original shallow arched head, with various masonry and render used as infill between the rectangular frames and the masonry. Presumably installed in the 70s when the property underwent significant renovations.

A couple of pictures may help.
FFG

[Amateurish]

Equus said:

Elderly said:

I pointed out that the house was Listed - i.e. there was a list of work done.

That isn't the meaning of 'listing'. The actual description of the building given on the statutory listing is quite brief.

You could potentially try to piece together the recent (post 1948) architectural history of the building from documentation on each individual LBC application held by the Local Authority, but that is also problematical and again the information may not be all that comprehensive (or reliable).

The listing says "Late C20 casements with glazing bars."

[Amateurish]

FlipFlopGriff said:

Amateurish said:

Thanks for all the advice so far, I will contact our local CO to discuss.

As for the existing windows, they are 20th-century replacements, single glazed and set within openings with an original shallow arched head, with various masonry and render used as infill between the rectangular frames and the masonry. Presumably installed in the 70s when the property underwent significant renovations.

A couple of pictures may help.
FFG

To see the condition of the timber or to see the style of the casements within the context of the property? It's timber framed with close studding and some victorian rebuilding in brick.

Edited by Amateurish on Thursday 20th February 12:01

[FlipFlopGriff]

Amateurish said:

To see the condition of the timber or to see the style of the casements within the context of the property? It's timber framed with close studding and some victorian rebuilding in brick.

Edited by Amateurish on Thursday 20th February 12:01

Just the stle of window for me. I'm no carpenter/joiner so couldn't really add much to the wood condition.
Does the glass have any character or just flat glass - not so easy to see when its raining?
FFG

[CubanPete]

My mate's (farm)house is listed.

The control officer said no to any changes to the windows.

He had them rebuilt (original frames) with thin double glazing and draught improvements regardless on the basis his house isn't really visible, and it won't be sold in his lifetime.

The neighbouring farm has windows that look like they're about to fall out, despite being far from short of money, so wonder if they have the same issue...

[pushthebutton]

FlipFlopGriff said:

SNIP

You can either take the whole panel off in teh summer or buy separate panels so you could then just remove the opener.
FFG

Thanks.

[FlipFlopGriff]

pushthebutton said:

Thanks.

I had another look at the fitting instructions and you can also add addiotonal magnets on the internal face of other panels so you could for instance remove an opener panel and attach it to a fixed panel, which I hadn't seen before. Saves losing or the other panel getting damaged. I read an article in the LPOC magazine which promted me to try some panels and I've been very impressed with the panels, the look, draught stopping and reduced noise for a good price.
FFG

[Lotobear]

Mono laminate thermal single glazing is an option which is often acceptable to CO's in my experience if they won't allow double glazing.

Our local CO will not accept double glazing of any type in any listed building in any circumstances (it's his personal hobby horse). It's frustrating and confusing for a lot of lay people because a neighbouring authority will usually allow it if sensitively designed.

One of the issues is the almost absolute power of CO's and a lack of national policy guidance on the vexed issue of double glazing in listed buildings. Some national clarity and consistency is needed IMO.