Am about to embark on the construction of my large windows, triple glazed, timber framed. After much searching have tracked down one of the products used by window manufacturers for thermal breaks in frames. As yet still to establish if it is available to my joiners in the required quantity but the info may be of interest to other potential window builders. The product is Purenit by Puren, will update if I get anywhere with sourcing stock.

There is an info sheet on the Puren website and I will pass on any info I get re. availability and minimum order requirements for the UK. Have asked the question so hopefully will have a response soon.

ikimiki, if its of interest the UK contact for Purenit is EH Smith, sustainable products division. They are in the process of sending a sample for my joiners to play with. djh, do Timbmet supply the raw product or in timber/purenit/timber laminated sections which are ready for machining to suit.