Replacing double glazing

TheProfessional

Hi all,

We have recently bought a house with a conservatory which has been converted to be part of a large kitchen diner (without building regulations). It gets cold which I assume is because of the window ratio to wall and who knows how much floor/ceiling/wall insulation there is without opening it up.

All of the windows are blown. They were installed about 20 years ago so not particularly surprised. They have condensation inside the two panes along with steam type marks.

On recommendations we got someone local to come round and coincidentally he was the one who fitted them to start with. We expected to replace the whole unit but he said it would be better value to just replace the glass with K type glass as the frames were solid and didn't need changing unless we wanted different style/colour

Does anyone think changing to K glass would improve the warmth as the advertising says it lets light in and a metal layer traps the heat in. Also because of that the tradesman says it doesn't always look perfectly clear. He also said he uses special spacers in the window which would help keep heat in

EssexExile

I would go with what the man says, seems silly to change the frames if they are still good. I assume they use plastic spacers now instead of metal to reduce heat transmission. He should be able to give you some figures for the u-value of K glass compared to clear.

ytfcmad

I'd rip the lot out, far too much plastic on display with poor sight lines. Replace with a single door and get rid of the little openers up top, just have full height side hung's all round, it will transform that room. (Google French Casement windows)
K Glass is old school, you want a soft coat low e glass not that you will notice much difference whichever you go with.
You can easily take up the window cill's to check on insulation too.

TheProfessional

Thanks for the comments. French casement windows do look good. We may get another local company to quote to see what full replacement is. 

I had a look Essexexile and yes seems there are non metal spacers which will help some. Every little will help as yesterday when I came down it was 13.9 degree in that area. It does feel warm when the direct sun is coming in which makes me think it will be roasting on the hottest summer days. We have never had a conservatory type room before so maybe that's normal.

With regard to K glass, low e etc there seems to be many options ytfcmad. 

I wonder if anyone can recommend a particular type of soft coat low e glass that might be best and not excessively expensive? Also what would I be looking at to replace this area with French casement windows with soft coat low e glass (possibly with Georgian bars as the front of the house has also) 
Considering replacing just the glass with K glass was about £1490 I am safely assuming it will be double that?

We did check out black aluminium frames but they look particularly expensive and as the rest of the house is white uPVC might look a little odd

Thoughts appreciated 

Jeepers_Creepers

TheProfessional said:

That's a nice room :-)   It also looks to be Southish facing? Well, at least not North. (There's something out there to the left that blocks lower Winter sun coming in the side windows?)

That used to be a connie, with presumably the dreaded polycarb roof? Which means it would have been pretty much unusable for parts of the years - extreme hots and colds - before. You've had the single biggest improvement carried out, and that's the 'proper' roof.

Have any rads been added to it? Ah...  Why is it cold? Largely, then, because it has no extra heating.

You've met the guy who originally built it? That's cool. Does he know whoever converted it afterwards - added the solid roof? It would be really useful to know (a) what's in the floor (any insulation?), (b) what's in the dwarf walls (any insulation?) and (c) what's in the roof (any youknowwhat?)

That info would tell you what's worth doing. For instance, if there's no insulation in the floor - if it's effectively a giant solid heat-absorbing slab - then anything you can add over that will help - even an 8mm layer of fibreboard. Does the kitchen also have these tiles?

If the roof is very poorly insulated, then even 35mm Thermal laminate Board (insulated p'board) stuck up there would make a huge difference. And if the dwarf wall is cavity with the inside skin also standard 'block' (and not thermal type), then there's potential to add insulation there too. 

But, all these solutions will cost many £100's, and might not actually solve the issue fully. What will? That's a secret*

Meanwhile, these glazing units have blown, and for cosmetic reasons alone they need replacing. It's therefore worth looking at what will make the biggest improvement, relative to cost. And I don't know the answer (but the answer is 'out there'). What I'd moot, tho', is that whatever glass you replace it with ain't going to make that room warm. For instance, these units have 'blown'? Guess what difference that makes to its thermal properties? Next to zilch. How much difference will 'coatings' make, or 'argon fills'? No idea, but I'd hazard minimal. I would go for these as long as they don't cost silly money, but would hesitate to do so if the cost is high in proportion to the advantage. That's going to need a bit of research and some sums.

And if these things don't actually make the room 'warm', it's simply because it needs proper heating in there. How much for the cost of an extra rad? A couple of £undred? And how much extra will this cost to run each year (bearing in mind that it'll only be needed for a few colder months, and that room will add warmth to the kitchen for much of the rest of the time)? I dunno - £50pa?

So, if there isn't a radiator in there to warm it up, that's the problem. Oh, and the *secret :-)

ytfcmad

TheProfessional said:

Thanks for the comments. French casement windows do look good. We may get another local company to quote to see what full replacement is. 

I had a look Essexexile and yes seems there are non metal spacers which will help some. Every little will help as yesterday when I came down it was 13.9 degree in that area. It does feel warm when the direct sun is coming in which makes me think it will be roasting on the hottest summer days. We have never had a conservatory type room before so maybe that's normal.

With regard to K glass, low e etc there seems to be many options ytfcmad. 

I wonder if anyone can recommend a particular type of soft coat low e glass that might be best and not excessively expensive? Also what would I be looking at to replace this area with French casement windows with soft coat low e glass (possibly with Georgian bars as the front of the house has also) 
Considering replacing just the glass with K glass was about £1490 I am safely assuming it will be double that?

We did check out black aluminium frames but they look particularly expensive and as the rest of the house is white uPVC might look a little odd

Thoughts appreciated 

Low E is Low E pretty much. K is a hard coat and has a slightly darker tint than say Planitherm which is a soft coat. Soft coats perform slightly better but not in a way that you will ever notice, price wise they are about the same.
You can mix the combination in your DGU's but you will always need one pane of Lowe E to conform to Doc L, I have a mix of anti sun, low e, acoustic, laminated and self clean in my conservatory.
As for spacer bars, they are all warm edge these days, you wont get a choice and all DGU's incorporate the latest warm edge technology.  
Don't bother with Georgian bars, they dont let light in, trap dirt and are very dated.
You can get Black PVC windows.

TheProfessional

Thanks both

Did a bit of Google image searching at French casement windows and sightlines etc. A whole world of window chat out there! 

We had a quote from a local company who said not to bother changing just the glass as the frames are old enough that the gaskets will be going, rubber is shrinking and will be going soon so change the whole lot. For grey inside and out, full length and opening (but with a central vertical bar as he said flying mullion would be a lot more expensive the total is £4300

He said leave the roof etc as it's not worth trying to do anything to it as already tiled 

We are going to get a other quote to see how this compares 

Jeepers_Creepers

Thanks for the update.

That all sounds very sensible, and it'll make for a stunning room - so ~£4k ain't bad for that.

By 'full-length' you mean the same overall window height as you currently have - retaining the dwarf wall - but just full-height glass units? Sounds good.

I still doubt it'll make a significant difference to the room's actual warmth in winter, tho', as I suspect that room is simply deprived of adequate heat. I'm guessing it's relying on the radiators in the kitchen'diner area?

Over the course of a year, tho', that room will probably provide more heat than it takes :-)

TheProfessional

Thanks. There is a vertical radiator between the 'conservatory' and kitchen on either side and we have a plug in mobile heater I think we will probably have to put on in the morning  when the temp reeeealy dips overnight. 

The plan is also to put some LVT down throughout kitchen diner lounge and that might feel a bit warmer than the current freezing tile.

Good to hear the quote doesn't sound too high. I did hope it would come in cheaper. Apparently if we had white rather than grey it would be £3500 rather than £4300.
He said soft coat low e with carbon edges.

Yes exactly full length from top of frame to top of dwarf wall rather then split as they are currently. We have had a few days of sun since I last logged in and it is DEFINITELY warmer in direct sunlight (which is probably obvious)

Jeepers_Creepers

It's going to be a lovely room - no question (it already is...)

I wasn't commenting on the actual quote as such as I've no idea if it represents good value - but just that you'll have a superb room for what is not much outlay in the scheme of things. If you'd need to build that from scratch, you'd be talking £20k+. Having said that, the quote doesn't seem at all unreasonable to me (it's quite a bit of work!).

Absolutely get more quotes. I suspect they won't vary that much - that is a lot of glass! Also consider aluminium; it tends to have a touch more quality; slimmer frames, less boxy, tends to operate very smoothly. But almost certainly more costly...

Out of interest - and you have nothing to lose - give https://www.gfdtrading.co.uk/ a call too. They did our extension in aluminium (Smart Visofold 1000) - 4m bifolds, 2 x windows, composite 'Durador', 2 large skylanterns for £10k fitted. (I have no issue with the item quality, but their fitters were  a bit pants - tho' personable...)

maxsteam

TheProfessional said:

he said it would be better value to just replace the glass 

It's not impossible to do this yourself. In your shoes I would try one pane first to see how it goes. You will need to measure the pane accurately and get the new one made. Then it's just a matter of removing the plastic strips that hold the pane in place and swapping the panes. If you've done it once, it's easier second time. It's certainly a lot easier to replace double glazed panes in uPVC windows than old-fashioned panes imho.