Green Building Forum - mitigating thermal bridging around Velux / Rooflights Tue, 19 Dec 2023 08:39:44 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 mitigating thermal bridging around Velux / Rooflights http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17729&Focus=300066#Comment_300066 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17729&Focus=300066#Comment_300066 Wed, 01 Feb 2023 23:53:59 +0000 number_thirty_three
We have plans to include two fairly small openable rooflights - looking at Velux or Fakro - in our loft conversion. Have scoured for guidance on how to minimise the bridging around the frames but it seems little has moved on since this post from over a decade ago, and the manufacturers still offer fairly limited solutions in this space:

http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=4112&page=1" >

Some specific questions:

1) One of the interesting ideas I've seen mentioned in a few previous posts is about constructing some kind of mini-SIP to house the Velux frame in. Has anyone got any pictures or links to anything detailing how this has been done successfully?

2) I'm planning on putting 80mm PIR above the rafters; can't find guidance on how to install Velux or Fakro in such a circumstance - presumably they have to be installed onto timber, not to PIR - so would we need to construct a raised timber frame above the rafters in line with the insulation, to secure the frame into? If so, then I guess that's introducing more thermal bridging - any ways to mitigate this? I've seen mention of wrapping Aerogel up the insides. Worth it?

2) Should we rethink having openable rooflights? The loft design has one rooflight in the bathroom, one in the bedroom, and then a large openable window on the dormer side. We're due to have MVHR. Do we need to be able to open the skylights, or should we consider being more radical and having them fixed to improve the overall thermal performance?). Feel like we will want cross-ventilation on warm summer nights... Obviously this is a personal choice kinda question but I'm curious what the folks on this forum would do.

Thanks]]>
mitigating thermal bridging around Velux / Rooflights http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17729&Focus=300078#Comment_300078 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17729&Focus=300078#Comment_300078 Thu, 02 Feb 2023 13:46:44 +0000 djh
e.g. https://www.lamiluxskylights.co.uk/rooflights/glass-skylight-fe-passivhaus.html]]>
mitigating thermal bridging around Velux / Rooflights http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17729&Focus=300156#Comment_300156 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17729&Focus=300156#Comment_300156 Mon, 06 Feb 2023 21:39:12 +0000 number_thirty_three