georgian sash windows

[the excited mariner]

Good evening.

I was wondering what the minimum dimensions would be, for glazing bars on 12 pane sash and case windows to suit double glazing.I was thinking the units would be 10 mm veiw line. Trying to match new build windows with existing house windows,that will never be a reality, but trying to acheive proportions and look.Been down slimline units a few years ago,just getting over it,had to take orginal glass out rotten windows from 1880 take them to slimline the put them into units ,fetched them back fitted into new windows,but thats a story for a rainy day.

your thoughts much appreciated

 

[MMUK]

Personally, I'd use a single sealed unit and fit astrigal bars over the top inside and out. It makes construction much easier and saves shed loads of time. I'd be tempted to fit 1/2" astrigals.

 

[RogerS]

Personally, I'd use a single sealed unit and fit astrigal bars over the top inside and out. It makes construction much easier and saves shed loads of time. I'd be tempted to fit 1/2" astrigals.

Sorry to disagree but on a period property that looks just plain naff.

To the OP...go with what ever matches the existing windows. If you are having to put in double glazing then if you can get away with 4 6 4 then you can get a heritage spacer that is only about 6mm tall which lets you keep the glazing bars a bit thinner. But you will never get them to look as thin and elegant as original Georgian windows. Sod double glazing.

 

[andypa]

I know that one of the big sash window makers in Edinburgh makes their double glazed Georgian sashes with 27mm wide astragals and uses 4-6-4 DG units.

Also, my neighbour has recently had some of his 6 over 1 sash windows replaced. I think they have wider astragals but don't look too bad from a distance :lol: The original single glazed look far more elegant.

 

[RogerS]

27mm? That must look hideous.

 

[srp]

27mm? That must look hideous.

They have to be at least 27 mm wide to hide the spacer bars within the rebate. That's why most people use a single unit and stick the bars on the outside and inside. I've done it both ways and the stick on bars look much better.

 

[Jacob]

When I was doing sashes I ended up only doing precise replicas and just said no to double glazing, hardwood, all modern tendencies. It just shifts your customer base but there was no chance of ever running out of work - you get to be known as the person who does only precise replicas etc and I'm still getting phone calls now.
So if it's a problem and you don't want to do it, just say no.

 

[RogerS]

I agree with Jacob 100%.

 

[richarnold]

I wish it was as simple as never having to do double glazed windows, but unless it's a listed building, current building regs just won't allow it. I love doing single glazed sashes, but sometimes you have to compromise. These windows were 4/6/4 units with a 28mm glazing bar.

 

[RogerS]

"current building regs just won't allow it"

They do if you are just repairing the sashes :wink:

 

[the excited mariner]

Thank you very much for your thoughts on the matter,its tricky one, you have the cost factor,ease of manufacture, reg requirements what the client wants ,which is when it gets difficult because they want super duper thermal effeincey and the fine georgian look.I think at end off the day all suggestions are suitable ,its just matching them to the clients demands and budget and explaining the pros and cons this is the rub.
I think 27 mm glazing bar is not slender, but as the fellow thats has posted his window photo has shown they can be done well.this i think would be the way to go for this one.My own preference in sash in case windows is single glazed brush seals good fitting working shutters and insulate the rest of the house to the max .oh a couple photos of windows with the slimline units
.

 

[Jacob]

"current building regs just won't allow it"

They do if you are just repairing the sashes :wink:

And if you don't tell them they don't know or care. You'd have to be careful on a new build if the BCO was a likely visitor, but as a rule they leave you alone.

 

[deema]

Just a thought, daft as it may be!
I wonder if you can achieve both objectives by glazing the entire window with a single pane of double glazed glass. The rebated part of the frame has fixed glazing bars that will sit against the glass, and the rebated side has a 'window frame' made up that will fit into the rebate with the glazing bars aligning with the other side. The thought being that with careful manufacturing and fitting the glazing bars will be slender, carrying no weight, and will apart from very close inspection give the appearance of individually glazed units?

 

[MMUK]

You can have double glazed units fitted with slimline back to back spacer bars to give the effect of individual units. Once glazed you then position the astragal bars over them

 

[richarnold]

"current building regs just won't allow it"

They do if you are just repairing the sashes :wink:

And if you don't tell them they don't know or care. You'd have to be careful on a new build if the BCO was a likely visitor, but as a rule they leave you alone.

This is all quite true, but unfortunately that's not the problem. What is a problem is when your customer tries to sell the property in the future, and they don't have the relevant paper work. solicitors can be a right pain sometimes, and if the sale fall through you know who is going to get the blame!

 

[RogerS]

"current building regs just won't allow it"

They do if you are just repairing the sashes :wink:

And if you don't tell them they don't know or care. You'd have to be careful on a new build if the BCO was a likely visitor, but as a rule they leave you alone.

This is all quite true, but unfortunately that's not the problem. What is a problem is when your customer tries to sell the property in the future, and they don't have the relevant paper work. solicitors can be a right pain sometimes, and if the sale fall through you know who is going to get the blame!

Repairs are not covered by Building Regs.

Only if you replace the entire window, frame and all.

Even then you simply answer 'it was like that when we bought it'. No-one buying a house cares anything about all this BS. They will buy the house because they like it.

 

[Jacob]

"current building regs just won't allow it"

They do if you are just repairing the sashes :wink:

And if you don't tell them they don't know or care. You'd have to be careful on a new build if the BCO was a likely visitor, but as a rule they leave you alone.

This is all quite true, but unfortunately that's not the problem. What is a problem is when your customer tries to sell the property in the future, and they don't have the relevant paper work. solicitors can be a right pain sometimes, and if the sale fall through you know who is going to get the blame!

Worry worry!! I think this problem is entirely imaginary.

 

[andypa]

I was getting a quote for some DG units at a place in Edinburgh today. They do a thin DG unit with a 7mm sightline for historic/listed/conservation areas. That might help :duno:

Also, at another place, saw a modern style timber sash window with 24mm thick DG units and 24mm wide through astragals Think they called them Swiss style astragals. No idea what that means :?