Tue, 04 Aug 2026 02:59:26 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7140&Focus=105566#Comment_105566 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7140&Focus=105566#Comment_105566 Fri, 18 Mar 2011 22:48:21 +0000 fostertom http://www.bdonline.co.uk/5014839.article?origin=BDweeklydigest:

"Inaccurate figures could lead to damaging and unnecessary interventions, warns SPAB

Heat loss through vernacular materials can be up to three times lower than expected, according to new research conducted for the Society for the Protection of Ancient Buildings (SPAB).

The standard U-value calculations used across the construction industry to assess thermal performance appear to underestimate the efficiency of traditional walls, according to Dr Caroline Rye from the University of Portsmouth.

Her research suggests that 79% of the traditionally built walls sampled – including timber, cob, limestone, slate, and granite – actually perform better than expected.

Jonathan Garlick, SPAB technical officer and project leader, said: “Amazingly, this research has not been carried out before in England. Accepted theoretical performance figures have long been used as a standard base measurement by professionals and homeowners when old buildings are being up-graded, altered or even assessed for Energy Performance Certificates, but are they correct? We believe that with some traditional materials our in-situ results prove that they are not. We appear to be actually underselling the thermal performance of our old buildings by not fully understanding them.

“Energy efficiency is becoming the key issue for people working with historic buildings. If we aren’t basing our approaches on the right figures to begin with, then we could, unintentionally, be doing untold, invasive damage.”

Here's the report:
http://www.spab.org.uk/downloads/Courses_2010/TheSPABU-valueReportFINAL.pdf]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7140&Focus=105569#Comment_105569 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7140&Focus=105569#Comment_105569 Fri, 18 Mar 2011 23:06:06 +0000 tony https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7140&Focus=105570#Comment_105570 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7140&Focus=105570#Comment_105570 Fri, 18 Mar 2011 23:07:20 +0000 tony https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7140&Focus=105572#Comment_105572 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7140&Focus=105572#Comment_105572 Sat, 19 Mar 2011 08:05:01 +0000 SteamyTea Does Equation 1 in the report convert it to a steady state condition as it is is using the sum of the temperature changes divided by the sum of the heat flows for the test period.
It is also worth looking at the magnitude of the measured and calculated U-Values, 6 had a U-Value under 1, 14 between 1 and 2 and 4 above 2. This can easily skew the results.

Kind of research I like as it is real. Did you want some real data on old buildings on another thread, friend of mine did some work on this a few years back, not sure if he has still got it though, he was never very good at backing up his data and the university used to wipe it all in the summer.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7140&Focus=105590#Comment_105590 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7140&Focus=105590#Comment_105590 Sat, 19 Mar 2011 11:04:54 +0000 fostertom https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7140&Focus=105591#Comment_105591 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7140&Focus=105591#Comment_105591 Sat, 19 Mar 2011 12:33:51 +0000 seanie