Green Building Forum - Aerogel for external wall insulation Thu, 04 Jun 2026 17:11:34 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 Aerogel for external wall insulation https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108528#Comment_108528 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108528#Comment_108528 Wed, 27 Apr 2011 23:17:13 +0100 rhamdu
I think we might get away with a thinner insulation treatment without planning permission, but aerogel seems to be the only material with adequate performance. Does anyone have any experience of EWI with aerogel, or know the pros and cons (other than the cost)?]]> Aerogel for external wall insulation https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108531#Comment_108531 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108531#Comment_108531 Thu, 28 Apr 2011 00:03:59 +0100 CWatters Aerogel for external wall insulation https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108535#Comment_108535 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108535#Comment_108535 Thu, 28 Apr 2011 07:43:54 +0100 Saint Aerogel for external wall insulation https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108536#Comment_108536 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108536#Comment_108536 Thu, 28 Apr 2011 08:13:52 +0100 Peter_in_Hungary Peter]]> Aerogel for external wall insulation https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108545#Comment_108545 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108545#Comment_108545 Thu, 28 Apr 2011 09:56:51 +0100 jms452
I started off thinking I was happy to spend more to get the best product until I found out just how expensive it is! 40mm might triple the cost of the EWI!]]> Aerogel for external wall insulation https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108551#Comment_108551 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108551#Comment_108551 Thu, 28 Apr 2011 10:27:06 +0100 Peter_S Is the property already rendered and therefore would not look much different with EWI and render to how it looks already? Will the 'charactor' of the property be altered substantially by rendering it?
Terraced type properties right on the street may not be a very practical use for EWI due to potential damage to the system at low level.
Is it possible to insulate internally with 100mm to the front wall?

Personally, I haven't seen an aerogel EWI system in use, but given the cost, would be unsure of using it in your situation anyway.]]> Aerogel for external wall insulation https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108558#Comment_108558 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108558#Comment_108558 Thu, 28 Apr 2011 12:13:08 +0100 Saint Aerogel for external wall insulation https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108559#Comment_108559 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108559#Comment_108559 Thu, 28 Apr 2011 12:13:19 +0100 Saint Posted By: Saint
Posted By: jms452started off thinking I was happy to spend more to get the best product until I found out just how expensive it is! 40mm might triple the cost of the EWI!


That's very true based on pure material cost but its used typically where available space is highly valued or restricted. Try and consider total project costs. In EWI for example the roof overhang may be insufficient for a thick build up and has to be exetended, there are no doubt other occasions where thicker solutions are more expensive than you'd first think.

Posted By: Peter_STerraced type properties right on the street may not be a very practical use for EWI due to potential damage to the system at low level.


Used in conjuction with a render board damage at street level would not be an issue, also the time for installation and finishing is vastly reduced

Posted By: Peter_SIs it possible to insulate internally with 100mm to the front wall?


As above, this is where an aerogel internal dry lining laminate comes into its own]]> Aerogel for external wall insulation https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108561#Comment_108561 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108561#Comment_108561 Thu, 28 Apr 2011 12:23:27 +0100 Saint Aerogel for external wall insulation https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108567#Comment_108567 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108567#Comment_108567 Thu, 28 Apr 2011 13:57:57 +0100 wookey
here we are: case study: http://www.aerogel.com/markets/Case_Study_House_Renovation_web.pdf

From this thread: http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3412

Not much detail in that case study, but you could probably get more from Proctor. Does show that it's been done though. I'd expect the cost as well as the location to be quite 'Swiss' :-)]]> Aerogel for external wall insulation https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108571#Comment_108571 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108571#Comment_108571 Thu, 28 Apr 2011 14:31:17 +0100 Peter_S
Used in conjuction with a render board damage at street level would not be an issue, also the time for installation and finishing is vastly reduced
true (for accidental damage at least), but then your getting back up to a 60mm (The Spacetherm brochure quotes a u-value of 0.23 using 36mm on a 220mm solid brick wall plus a render board and render) thickness which may not be acceptable unless the entire street is doing the same (possible good solution in local authority grant funded scenarios?). Malicious damage is another matter however which is where my concerns for any EWI system on houses directly onto the street stem from.

Posted By: Peter_SIs it possible to insulate internally with 100mm to the front wall?


As above, this is where an aerogel internal dry lining laminate comes into its own

I agree but it will be down to how much is that extra floor space worth internally. Hopefully the cost of aerogel will reduce significantly with increased use making these questions obsolete?]]> Aerogel for external wall insulation https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108576#Comment_108576 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108576#Comment_108576 Thu, 28 Apr 2011 15:03:12 +0100 john_connett
http://www.iea-shc.org/task37/events/exco67/4.Herkel-Concept_Analysis_and_Development.pdf

It was developed with The Fraunhofer Institute for Solar Energy Systems. Looks like a very clever system with a small range of different sizes that can be cut to shape without compromising the vacuum panels. When enquired about it some time back it was not available commercially. However, it now appears to be available at least in Germany:

http://www.sg-weber.de/waermedaemmung-wdvs/erfolgreich-planen/innovationen/webertherm-lockplate-vakuum-wdvs.html

Don't know what the minimum thickness would be but it seems to be applied in two overlapping layers before rendering. Unfortunately, I don't read German ...]]> Aerogel for external wall insulation https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108577#Comment_108577 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108577#Comment_108577 Thu, 28 Apr 2011 15:53:32 +0100 Saint Posted By: Peter_S(The Spacetherm brochure quotes a u-value of 0.23 using 36mm on a 220mm solid brick wall

Peter, I see you're having similar problems to me when quoting!

That Spacetherm reference is either a misquote or its wrong in the brochure. The U value of a solid brick wall is taken as 2.1 W/m2K i.e. an R value of 0.476. The thermal conductivity of Aerogel is 0.013-0.014 say 0.0135 so the R of 36mm of aerogel is 2.666.
Add that to the 0.476 and you have an R of 3.142 and therefore a U value of 0.32 W/m2K.

Aerogel's Spaceloft (Proctors call it Spacetherm) is no longer available in 9mm layers. It is now 5mm or 10mm.
So using 4 layers of 10mm the R is 2.962. Add that to the 0.476 and you get an R of 3.439 or in other words a U value of 0.29 W/mK. Allowing for thermal bridging through fixings and you're safe at 0.30 W/m2K

I agree that it depends on how the adjacent properties compare in this exercise. In theory at least or perhaps only you could use a 9mm render board, scrim the joints and finish with a textured paint, the whole build up just over 50mm.
Alternatively the solution would be to line internally. The same thickness i.e. 40mm + 9mm mag board could be used]]> Aerogel for external wall insulation https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108581#Comment_108581 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108581#Comment_108581 Thu, 28 Apr 2011 17:00:44 +0100 Peter_S I don't think I have used the quote feature before. Looks like its a case of 'practice makes perfect' as with most things in life :wink:

Going off subject a touch, what do people generally think about use of EWI in this type of situation? Are we in danger of spoiling the character of the local vernacular if everyone tries to insulate their properties this way, even though technically is probably the best option for many?

Will try to find any related threads on that.

Pete]]> Aerogel for external wall insulation https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108596#Comment_108596 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108596#Comment_108596 Thu, 28 Apr 2011 19:48:44 +0100 rhamdu Posted By: Peter_SThis throws up all sorts of questions regarding streetscape and EWI generally.
Is the property already rendered and therefore would not look much different with EWI and render to how it looks already? Will the 'charactor' of the property be altered substantially by rendering it?
Terraced type properties right on the street may not be a very practical use for EWI due to potential damage to the system at low level.
Is it possible to insulate internally with 100mm to the front wall?

I think the planning issue is appearance, not land ownership. Most houses here have rainwater pipes, porches, bay windows and other bits that stick out into the street. I just don't think the planners liked the idea of bringing the whole frontage forward.

IMHO our proposal would improive the appearance of the street. The property is currently 'stone'-clad and painted dark blue. Ye-es! The historical look for Brighton terraces is rendered and painted. So the proposed silicone render system would be in keeping with 'local vernacular', in a way that stone cladding is not.

Interestingly, our property already protrudes 40mm into the street, thanks to fake-stone slabs and adhesive. Suppose I were to remove the slabs + adhesive and replace them with aerogel and silicone render system totalling 40mm. The wall surface would not protrude any further than it does now.

We could insulate internally upstairs, but on the ground floor we have already fitted a kitchen which we don't want to disturb. Plus I'm totally sold on the thermal and weatherproofing advantages of external insulation.

Thanks for all the comments so far. At least I have some options...]]> Aerogel for external wall insulation https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108598#Comment_108598 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108598#Comment_108598 Thu, 28 Apr 2011 20:21:33 +0100 jamesingram I not up on planning , but i was under the impression they had to give some leeway in this area.

Removing the existing 'out of character' cladding and returning to the local vernacular only a more few inches out sounds a excellent solution .
Next one down from Areogel is phenolic, have you looked into what 40-75mm might give you , perhap offering a compromise to planning.]]> Aerogel for external wall insulation https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108602#Comment_108602 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108602#Comment_108602 Thu, 28 Apr 2011 21:44:44 +0100 tony
Proof of the pudding is the stick on stone cladding, clearly that protruded and nothing said.]]> Aerogel for external wall insulation https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108632#Comment_108632 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108632#Comment_108632 Fri, 29 Apr 2011 13:25:43 +0100 CWatters Aerogel for external wall insulation https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108766#Comment_108766 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108766#Comment_108766 Tue, 03 May 2011 13:44:06 +0100 djh Posted By: john_connettIt might be worth investigating the Lockplate vacuum insulation system which claims to reduce the required insulation thickness by a factor of three
But note that vacuum panels are very vulnerable to damage. Any hole releases the vacuum and the performance disappears. So there'd need to be an impact-resistant render board or something and some way to make sure nobody ever put a screw into it etc.

Vacuum insulation seems to me like phase-change materials. Great idea but too many practical problems in most applications. Perhaps some future version will be more usable.]]> Aerogel for external wall insulation https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108769#Comment_108769 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=108769#Comment_108769 Tue, 03 May 2011 14:06:56 +0100 James Norton
More often than not in my experience the officer realises this after validating the application then has to frantically back track - easiest way from their point of view is just to refuse the application.

Was it actually an application for planning permission or an enquiry as to whether it was permitted development or even as above just pre application guidance? If a full application then there should be formal reasons for refusal citing specific policy references etc.

The specific refuting of these reasons forms the basis of appeal and / or a resubmission.

J]]> Aerogel for external wall insulation https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=207553#Comment_207553 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7325&Focus=207553#Comment_207553 Sat, 23 Aug 2014 17:46:35 +0100 Mike George