Insulated panel behind louvre window

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Established Member
28 Aug 2016
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I have some interesting little windows to make for an old barn.

It's a nice old building, downstairs is 2 stables and tack room, upstairs has always just been storage but they are converting it into a more usable space by insulating walls etc.

I am making some replacement windows for it as existing ones are rotten and falling out. They are matching existing which have open wooden louvres in the bottom and a small pane of glass in a gothic arch in the top, see rough sketch
gothic window.jpg

It's not a really posh job but obviously I need to seal the back of the louvred section of the window, was looking at making a panel to screw on the back of the bottom of the window behind the louvres. I was thinking of maybe 25 mm Kingspan sandwiched between 2 pieces of 12 mm ply with an edging lath around. Anyone see a problem with this, is glass fibre type insulation better in this situation as kingspan might sweat? Should the panel be vented to avoid this or am I overthinking things? Want the panels to screw off for repainting louvres further down the line.

Thanks in advance for your thoughts.


  • gothic window.jpg
    gothic window.jpg
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