Double/Triple glazing box sash windows(7 Posts)
Having acquired a home with beautiful views across open countryside we find ourselves with a room with a view that can only be enjoyed on a warm day or wrapped in a duvet.
We seriously need to sort out some sort of modernisation of the sash windows incorporating double glazing or even triple.
Have had leaflets for ventrolla and the box sash window company but it's all still a mystery to me as to how they work in stopping draughts.
Has anyone any experience/success re improving warmth in their sash-windowed home by having the windows replaced by one of these companies ?
They seem to charge a lot of money so I'm keen to make sure we aren't chasing the impossible and I realise that old homes need ventilation and box sashes provide it (in the form of draughts !)
When we renovated our house we had double glazed sash windows from this company. The glass is one unit and they glue on the glazing bars so they look like traditional windows.
I'm pretty sure they are far more draught proof than traditional windows, but because they are still wood, and still of sash construction the rooms facing the prevailing wind do tend to be colder. Having said that, most days I don't realise how cold it is until I venture out, so they must be doing a pretty good job.
There are two issues here.
One is to prevent uncontrolled ventilation i.e. stop the drafts. Systems like the one offered by companies such as Ventrolla are fairly effective. I have specified them on several restoration projects for various buildings such as schools, hotels and private houses. I must say I and my clients were quite pleased with the results.
The second issue is heat loss through single glazing which is usually solved by installing additional 'secondary' glazing or in extreme cases by replacement of the entire window. When this is done the new windows usually incorporate draft sealing as part of the package.
Secondary glazing is easier but often creates more problems in the form of condensation.
Replacement windows provide much scope for fun and games as regards products and workmanship, consequential repairs, damage to finishes and so on.
As your main difficulty seems to be drafts I would suggest that Ventrolla or similar would be the most cost effective route. This would have the additional benefit of retaining your original windows which is always a more elegant and satisfactory solution from the point of view of conservation (especially if your house is a perioud property as well as natural resources).
One final point, if your house is period, then check if it is Listed. This will limit your options if you decide to plump for replacement.
Old wooden sash windows don't seal very well, particularly if the wood is rotting, so air can flow into the room from outside. The companies that refurbish the windows will replace any rotting wood and use modern technology to get a better seal round the windows, stopping the draughts.
I have seen wooden sash windows built with double glazed units, which look fantastic. You can hardly tell they're double glazed unless you get up close. They're not cheap but if you want to retain the look of a period property I think they're worth considering.
get lots of quotes! these companies charge unbelievable amounts, but there seems to be no end of them in the phone book.
i was going to get ours redone, but felt so shocked when i got the quotes that we've put it off as long as possible.
hi, double glazed is possible but I urge you to think about triple glazing in sash windows.
I have a vested interest in that I make sash windows for a living, however DG (two sheets of 4 mm glass is already nearly 3 times the glass weight of single glazing.....because most old single glazing was 1/8 or 3mm)
going for three sheets of 4mm glass will make glass weight 4 times heavier and thats really hard to make the sash slide without effort!
Also three sheets of glass will make the room darker because (just like opening a car window, the outside looks brighter, three sheets will affect the brightness.
always repair where necessary but dont be affraid to replace if they are past it, you can get very authentic PVC and wooden sash windows
I found this review site recently that may help find local companies and they have a section that explains about window energy ratings here www.doubleglazingcompanies.com/knowledge/product-accreditations/WER/?3
hope this helps
Wow, thanks for all the information everyone.
We are definately not a listed property thank heavens.
Time to start getting quotes I think, we have identified that one particular side of the house is the main problem and this just has two very large bay windows in so I think we'll have to give triple glazing a miss as the main section is already quite heavy.
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