Green Building Forum - passive house foundations Wed, 10 Jun 2026 01:20:43 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 passive house foundations https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9729&Focus=159540#Comment_159540 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9729&Focus=159540#Comment_159540 Sun, 21 Oct 2012 13:40:38 +0100 neilgorswift
I've just received my copy of the passivhaus-bauteilkatalog its very informative
Quite a few details note "warm foot" components that act as structural insulation at the base of a load bearing wall. Is it an aircrete type block where you can get down to 0.11W/mk and minimise the cold bridge a little. Or specialist items like marmox / perinsul or schock type blocks. I suspect the latter are expensive when they are required under a 365 durisol block?

What do the Europeans use here! Your thoughts and views welcome]]> passive house foundations https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9729&Focus=159617#Comment_159617 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9729&Focus=159617#Comment_159617 Mon, 22 Oct 2012 13:12:47 +0100 djh passive house foundations https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9729&Focus=159666#Comment_159666 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9729&Focus=159666#Comment_159666 Mon, 22 Oct 2012 23:40:28 +0100 neilgorswift
Honeycomb brick outside wall, ETICS/slab foundation,insulated upper side, wet screed

Theres another whats ETICS ?]]> passive house foundations https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9729&Focus=159669#Comment_159669 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9729&Focus=159669#Comment_159669 Mon, 22 Oct 2012 23:58:51 +0100 nikhoward passive house foundations https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9729&Focus=159713#Comment_159713 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9729&Focus=159713#Comment_159713 Tue, 23 Oct 2012 14:25:27 +0100 Viking House http://www.viking-house.co.uk/passive-slab-insulated-foundations.html
All going well we'll start 25 Passive Houses in Hollyhead before the end of the year, we usually Solar Heat Passive Houses, this reduces the heating demand from 15kwh/m2.annum to 3kWh/m2.annum and reduces the hot water demand to 3kWh/m2.annum.

I'm not a fan of the Aircrete block method because their Lambda changes when they get wet, my opinion is biased.]]> passive house foundations https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9729&Focus=159747#Comment_159747 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9729&Focus=159747#Comment_159747 Tue, 23 Oct 2012 23:54:11 +0100 djh Posted By: neilgorswiftNo just description titles:

Honeycomb brick outside wall, ETICS/slab foundation,insulated upper side, wet screed
OK, I have the book now. I think you're looking in the wrong place. I think you're looking at the 'Connections' chapter, at something like AWm 05 - EFo 01. You need to look at the description of the wall and slab separately, in the earlier chapters. So you can find AWm 05 in 'Outside Walls' and it tells you there the 'Usual construction' and the 'Alternative construction'.

However, I agree it is vague about the 'warm foot'. Possibly it is described somewhere else in the book but I haven't been able to find it. They give a range of lambda values for it from 0.1 to 0.3 W/m.K, so I think its anything the engineer is happy with that gives you enough strength and a low enough lambda. Aerated concrete and foam glass panels get mentioned elsewhere.

Theres another whats ETICS ?

Google shows that means 'External Thermal Insulation Composite Systems'. It's the European term for what we call EWI with our glorious 'call it anything as long as its not the same as other Europeans' attitude.

Posted By: Viking HouseI'm not a fan of the Aircrete block method because their Lambda changes when they get wet, my opinion is biased.

In this particular detail, the aircrete block, or whatever it is, is inside the DPM. But I do like your foundation slab system!]]> passive house foundations https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9729&Focus=159970#Comment_159970 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9729&Focus=159970#Comment_159970 Sat, 27 Oct 2012 14:36:48 +0100 neilgorswift I costed the aircrete block, marmox, perinsul and Shoeck Novomur systems. Aircrete comes out the cheapest but i agree with Viking its not the best solution, even when dry as structurally its touch and go.
Just had a meeting with my engineer and he's comfortable with the raft with eps insulation below slab now so i am off in that direction.

have had some costs from Atlas and Izodom for their systems - pretty expensive although polish izodom is cheapest but not the neatest edge detail. Thinking Knauf polyfloor may be cheapest to use as it's just simple slab insulation T&G. Anybody got any other value for money solutions?]]>