Green Building Forum - Is there anyone who does a breathable closed panel kit? Thu, 16 Apr 2026 18:01:23 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=240579#Comment_240579 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=240579#Comment_240579 Sat, 14 May 2016 19:09:13 +0100 jwd
Cheers]]> Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=240582#Comment_240582 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=240582#Comment_240582 Sat, 14 May 2016 19:46:52 +0100 tony
Masonry can be vapour open but it is dangerous in terms of rot and interstitial condensation to have vapour open and timber frame and the better insulated you are the colder the outside of your frame will get.]]> Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=240586#Comment_240586 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=240586#Comment_240586 Sat, 14 May 2016 20:16:34 +0100 Ed Davies
http://www.carbondynamic.com/home.aspx

Wasn't there a company doing straw bale panels like this in the west country? Maybe in Bath?]]> Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=240588#Comment_240588 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=240588#Comment_240588 Sat, 14 May 2016 21:07:26 +0100 janoska666
This outfit do prefab at a decent price. Exemplary quality and price. Put PV on the roof and away you go

see www.sunhouse.fi]]> Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=240592#Comment_240592 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=240592#Comment_240592 Sat, 14 May 2016 21:52:42 +0100 Ed Davies Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=240598#Comment_240598 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=240598#Comment_240598 Sat, 14 May 2016 23:39:17 +0100 Gotanewlife Posted By: Ed DaviesLot of FUD about this evening, isn't there? You mean about Grexit I assume......]]> Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=240602#Comment_240602 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=240602#Comment_240602 Sun, 15 May 2016 09:13:26 +0100 Ed Davies Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=240670#Comment_240670 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=240670#Comment_240670 Mon, 16 May 2016 10:27:51 +0100 djh
You may be thinking of Modcell but I think it may be worth looking at Ecofab http://www.eco-fab.co.uk/

I think there are others if the OP searches for pre-cut timber homes but I don't know enough about any of them to make a suggestion.]]> Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=241016#Comment_241016 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=241016#Comment_241016 Fri, 20 May 2016 17:09:28 +0100 Rex
http://www.scandicom.biz/index.php?option=com_contact&view=contact&id=1&Itemid=5

They went into liquidation while my house was being built, but by that time, we had all the timber on-site, so everything was fine. They re-financed and started again as a smaller operation. Was very impressed with the t/f. I had open panels with Warmcell installed later, but they may do closed panel construction.]]> Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=241046#Comment_241046 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=241046#Comment_241046 Fri, 20 May 2016 23:29:35 +0100 Gotanewlife ]]> Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=241389#Comment_241389 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=241389#Comment_241389 Wed, 25 May 2016 20:33:56 +0100 ComeOnPilgrim Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310298#Comment_310298 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310298#Comment_310298 Wed, 25 Feb 2026 15:19:44 +0000 Andrew McAvoy
So …Where not detailed properly it can be a disaster.

I’ve built up wall panels on site from simple timber members with for instance more breathable MagPly on the exterior, ran the condensation risk calcs and they are much better, comply and remove the risk.

Further .. the step away from OSb and toward moisture permeable construction methods - allows for the use of warmer and less toxic insulation such as Sheepswool or cellulose fibre.
And the methodology ten allows for adding further layers of breathable insulation externally such as Insulation foil to move easily up to super insulation levels in line with Germany, but without the passive house side effects of living in a hometically sealed box .. if that’s not your desire.

It’s not for everyone.
Have tackled whole houses , extensions and upgrades to fabric this way over the last 25 years and found no issues .
Examples at
www.retoolarchitecture.com]]> Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310299#Comment_310299 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310299#Comment_310299 Wed, 25 Feb 2026 15:20:52 +0000 Andrew McAvoy Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310300#Comment_310300 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310300#Comment_310300 Wed, 25 Feb 2026 15:21:13 +0000 Andrew McAvoy ]]> Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310301#Comment_310301 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310301#Comment_310301 Wed, 25 Feb 2026 15:23:47 +0000 Andrew McAvoy Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310302#Comment_310302 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310302#Comment_310302 Wed, 25 Feb 2026 16:16:04 +0000 fostertom
The construction (for southern England at least) that works extremely well when modelled in WUFI, which I design and specify whenever suitable, uses 11mm OSB3 gapfilling glued and screwed incl all edges, on the outside of stud framing. Warmcel blown insulation between, plasterboard & skim inside, which may be punctured by trades. EPS or woodfibre glued like EWI outside the sheathing, choice of claddings like any EWI. No VCL. The OSB, along with the blown Warmcel, serve as robust airtight layer, but are more than enough vapour permeable, as is the EPS - another 'non breatheable' myth. This is for roof slopes as well as walls, forming a seamless 'tea cosy' of both insulation and airtightness at the eaves.

Posted By: Andrew McAvoypassive house side effects of living in a hometically sealed box
Another myth]]> Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310305#Comment_310305 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310305#Comment_310305 Wed, 25 Feb 2026 20:56:18 +0000 djh Posted By: Andrew McAvoywithout the passive house side effects of living in a hometically sealed boxAs somebody who lives in a passivhaus, I'm intrigued to know what side-effects there may be? Apart from not needing any heating this week, and having the best ventilation of anywhere I've ever lived, I can't think of many.]]> Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310307#Comment_310307 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310307#Comment_310307 Thu, 26 Feb 2026 09:46:17 +0000 sgt_woulds
Straw SIPs:

Modcell - https://www.modcell.com/
Ecococon - https://ecococon.eu/gb/


Closed Panel:

Oakwrights - https://elements.oakwrights.co.uk/passive-wall-system
Arfon - https://arfontimberframes.co.uk/
MBC - https://mbctimberframe.co.uk/passive-wall/
PYC - https://pycconstruction.co.uk/what-we-offer/build-system/


Timber frame kits / systems:

Kithurst - https://kithursthomes.com (see also: https://webuildeco.com )
PH15 - https://www.phhomes.co.uk/ph15-system/
Natural Building Systems - https://naturalbuildingsystems.com/
Lowfield - https://www.lowfieldtimberframes.co.uk/low-energy/]]> Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310308#Comment_310308 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310308#Comment_310308 Thu, 26 Feb 2026 10:02:23 +0000 sgt_woulds
Unfortunately in the UK it does not have very good airtightness - European spec OSBs have higher testing standards.

In Europe we specify our buildups inside to outside:

Plasterboard
Battened service void - can be filled with flexible woodfibre
15mm OSB3 fully taped and sealed for vapour control (acts as V-VCL), air tightness, and racking strength
I-beams / timber studs with woodfibre insulation
Woodfibre external sheathing boards (Either directly rendered or batten and rainscreen)

No membranes or foils used any where in the construction.


In the UK we have to specify smart ply and similar (plastic coated but breathable) instead of the OSB to ensure air tightness and breathability]]> Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310309#Comment_310309 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310309#Comment_310309 Thu, 26 Feb 2026 13:41:19 +0000 fostertom
I met a Smartply boffin at my WUFI Training in Dublin, discussed with him the need, which he was well aware of. He said Smartply were indeed considering what to do about it, would invite me on a consultation panel. Nothing happened, except Smartply introduced their plastic coated variant. Exactly wrong ("plastic coated but breathable"? I don't think so) . What's needed is airtightness but vapour-open, not crude VCL thus airtightness.

I heard Peter Warm, the UK grand daddy of PH Certification, say ' I've never met a building that failed airtightness because of OSB3'. Good enough for me. Plus, I design/specify the OSB3 in team with blown-in Warmcel, which has significant airtightness itself. The two add together, into an adequately airtight combo that's foolproof to construct (gapfilling expanding glue) and very robust longterm - no plastic membranes or tapes to deteriorate or go gappy within months (as I've heard airtightnes guru Paul Jennings describe), and somewhat self-healing if carelessly punctured in future.]]> Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310312#Comment_310312 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310312#Comment_310312 Fri, 27 Feb 2026 07:47:15 +0000 PeterStarck Posted By: fostertomI heard Peter Warm, the UK grand daddy of PH Certification, say ' I've never met a building that failed airtightness because of OSB3'. Good enough for me. Plus, I design/specify the OSB3 in team with blown-in Warmcel, which has significant airtightness itself. The two add together, into an adequately airtight combo that's foolproof to construct (gapfilling expanding glue) and very robust longterm - no plastic membranes or tapes to deteriorate or go gappy within months (as I've heard airtightnes guru Paul Jennings describe), and somewhat self-healing if carelessly punctured in future.

My last new self build used a 350mm portal I-beam timber frame with exterior racking using 15mm OSB3. It was fully filled with Icynene and we did not use any membranes or tapes. Around the windows and doors we used two strips of Compriband and the Soudal SWS system. We achieved an average airtightness of 0.47 ACH.]]> Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310313#Comment_310313 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310313#Comment_310313 Fri, 27 Feb 2026 08:03:40 +0000 fostertom Interesting, "two strips of Compriband and the Soudal SWS system". How did you decide on that triple seal? Published advice, your previous experience, or just super-cautious?]]> Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310325#Comment_310325 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310325#Comment_310325 Sun, 01 Mar 2026 12:07:42 +0000 Rex https://mbctimberframe.co.uk/) are constructing a steel framed house near me and to date, I am impressed with how their panels look. Seems to be good quality. But what do I know as only a casual observer?]]> Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310331#Comment_310331 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310331#Comment_310331 Mon, 02 Mar 2026 07:55:34 +0000 PeterStarck Posted By: fostertomV gd Peter. I don't suppose you repeated the airtightness test 6months/5yrs down the line?
Interesting, "two strips of Compriband and the Soudal SWS system". How did you decide on that triple seal? Published advice, your previous experience, or just super-cautious?

We had two tests carried out 20 months apart and the results were the same. For the first test, all surfaces were finished but there was no second fix, bathrooms, kitchen or compact unit fitted. For the second test the house was complete. For sealing the windows and doors I guess it came in the super-cautious category.]]> Is there anyone who does a breathable closed panel kit? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310332#Comment_310332 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266&Focus=310332#Comment_310332 Mon, 02 Mar 2026 10:41:55 +0000 fostertom