Green Building Forum - Cheapest material to build an outside wall with? Tue, 23 Jun 2026 23:30:56 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 Cheapest material to build an outside wall with? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248856#Comment_248856 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248856#Comment_248856 Tue, 25 Oct 2016 23:57:49 +0100 tony Cheapest material to build an outside wall with? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248857#Comment_248857 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248857#Comment_248857 Wed, 26 Oct 2016 00:54:40 +0100 Nick Parsons
Cob?]]> Cheapest material to build an outside wall with? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248865#Comment_248865 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248865#Comment_248865 Wed, 26 Oct 2016 08:18:23 +0100 delprado Cheapest material to build an outside wall with? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248866#Comment_248866 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248866#Comment_248866 Wed, 26 Oct 2016 08:25:57 +0100 barney
Barney]]> Cheapest material to build an outside wall with? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248869#Comment_248869 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248869#Comment_248869 Wed, 26 Oct 2016 08:48:45 +0100 Peter_in_Hungary Cheapest material to build an outside wall with? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248875#Comment_248875 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248875#Comment_248875 Wed, 26 Oct 2016 09:18:07 +0100 fostertom
1. Cost to client paying ordinary conservative UK builders i.e. all materials bought, all labour and project management paid for.

Then there's 2 variants to that -

1a. to Building Regs standard

1b. Eco build i.e. approaching PH standard]]> Cheapest material to build an outside wall with? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248879#Comment_248879 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248879#Comment_248879 Wed, 26 Oct 2016 10:12:19 +0100 Peter_in_Hungary
In my book an outside wall could be in the garden or boundary wall etc.

If its an external wall to a building then I would modify my answer above to concrete block and EWI, because of ease of construction and the need for flat surfaces, however collected (free) stone would still be cheaper if labour was not an issue]]> Cheapest material to build an outside wall with? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248891#Comment_248891 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248891#Comment_248891 Wed, 26 Oct 2016 12:26:26 +0100 ringi Posted By: delpradoI think its probably straw bale,

This puts up the cost of foundations due to the width of the wall, and also reduces the size of your rooms unless you got lots of land and new planning issues on the outside size of the building.]]> Cheapest material to build an outside wall with? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248896#Comment_248896 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248896#Comment_248896 Wed, 26 Oct 2016 13:27:47 +0100 fostertom Cheapest material to build an outside wall with? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248906#Comment_248906 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248906#Comment_248906 Wed, 26 Oct 2016 14:52:26 +0100 djh Cheapest material to build an outside wall with? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248907#Comment_248907 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248907#Comment_248907 Wed, 26 Oct 2016 15:15:32 +0100 fostertom Cheapest material to build an outside wall with? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248913#Comment_248913 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248913#Comment_248913 Wed, 26 Oct 2016 16:33:23 +0100 ringi
Given enough land, and being allowed enough ridge height, so I can have the “ground” floor above the level the bales start at, they could be a nice system.]]> Cheapest material to build an outside wall with? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248928#Comment_248928 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248928#Comment_248928 Wed, 26 Oct 2016 20:36:17 +0100 djh Posted By: ringiHow do you stop the cold bridge at the floor with bales, as I expect they need to be supported under their full width with concrete, so stopping a passive foundation being used?
I have a bale passivhaus on a passive slab, so QED. There's no 'standard' solution. What we did was to build a passive slab with a separate ring beam - a lot like http://www.viking-house.co.uk/images/LLf.jpg The ringbeam is 260 mm wide and the EPS either side are 125 mm external and 100 mm internal. Then we built a timber ladder structure out of 4x2 that is bolted to the ringbeam and overhangs the EPS on each side to the width of the bales (470 mm). The ladder was topped with 18 mm ply and the bales rest on that. Somebody on the Navitron forum built an experimental rig that demonstrated the 18 mm ply was plenty strong and stiff enough to do the job of supporting a house. I'm embarrassed to say that I forget who! The ladder is filled with technopor foamed glass insulation.

Given enough land, and being allowed enough ridge height, so I can have the “ground” floor above the level the bales start at, they could be a nice system.

Ground floor above the bales? Don't understand. You want the bales above the floor so that water spilled on the floor doesn't track into the bales.]]> Cheapest material to build an outside wall with? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248933#Comment_248933 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248933#Comment_248933 Wed, 26 Oct 2016 22:32:29 +0100 ringi
How did you get building control to agree to it?
Am I right to assume that the bales provided all the support to the roof and 1st floor?
How did you cope with the bales compressing over time while keeping air tightness?]]> Cheapest material to build an outside wall with? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248947#Comment_248947 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=248947#Comment_248947 Thu, 27 Oct 2016 09:55:52 +0100 djh Posted By: ringiHow did you get building control to agree to it?
Engineer's signature - same as any other structural question.

Am I right to assume that the bales provided all the support to the roof and 1st floor?

Not quite. In an area along the south side where ground floor windows are close together they get some help from the 4x2 window framing.

How did you cope with the bales compressing over time while keeping air tightness?

Bales are 'precompressed' during building and don't compress much after that. The plaster skins restrict further movement; the wall is really a composite panel. Indeed I believe the engineer's calculations disregard the support from the bales and only consider the strength of the plaster skins. Given that on some houses there are gaps between the plaster and the foundation, this isn't entirely realistic! But it seems to satisfy bureaucracy.]]> Cheapest material to build an outside wall with? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=249007#Comment_249007 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14651&Focus=249007#Comment_249007 Fri, 28 Oct 2016 09:26:31 +0100 Roger