Green Building Forum - How tight is tight? ( all discussion in m3/h/m2 @ 50Pa ) Mon, 25 May 2026 09:21:27 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 How tight is tight? ( all discussion in m3/h/m2 @ 50Pa ) https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=67#Comment_67 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=67#Comment_67 Wed, 31 Jan 2007 22:24:26 +0000 tony
Would you accept a window open all the time? a door? both halves of a patio door not there all winter?]]> How tight is tight? ( all discussion in m3/h/m2 @ 50Pa ) https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=68#Comment_68 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=68#Comment_68 Wed, 31 Jan 2007 22:32:41 +0000 Mike George
Is there a conversion factor for ach at normal air pressure. These are the values I normally use?]]> How tight is tight? ( all discussion in m3/h/m2 @ 50Pa ) https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=71#Comment_71 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=71#Comment_71 Wed, 31 Jan 2007 22:49:55 +0000 nigel How tight is tight? ( all discussion in m3/h/m2 @ 50Pa ) https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=88#Comment_88 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=88#Comment_88 Thu, 01 Feb 2007 16:33:53 +0000 tony
I agree 10 is rubbish anything more than one is too much for me.]]> How tight is tight? ( all discussion in m3/h/m2 @ 50Pa ) https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=91#Comment_91 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=91#Comment_91 Thu, 01 Feb 2007 16:45:29 +0000 nigel How tight is tight? ( all discussion in m3/h/m2 @ 50Pa ) https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=100#Comment_100 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=100#Comment_100 Thu, 01 Feb 2007 18:29:24 +0000 ecoworrier I guess the answer is as tight as possible...............

I'm not helping am I?]]> How tight is tight? ( all discussion in m3/h/m2 @ 50Pa ) https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=101#Comment_101 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=101#Comment_101 Thu, 01 Feb 2007 18:33:27 +0000 Mike George How tight is tight? ( all discussion in m3/h/m2 @ 50Pa ) https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=106#Comment_106 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=106#Comment_106 Thu, 01 Feb 2007 20:21:59 +0000 Guest
Paul in Montreal

p.s. I registered but haven't received confirmation of my username/password yet so this will be anonymous]]> How tight is tight? ( all discussion in m3/h/m2 @ 50Pa ) https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=117#Comment_117 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=117#Comment_117 Thu, 01 Feb 2007 21:16:22 +0000 tony How tight is tight? ( all discussion in m3/h/m2 @ 50Pa ) https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=128#Comment_128 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=128#Comment_128 Thu, 01 Feb 2007 22:18:13 +0000 Guest
Paul in Montreal]]> How tight is tight? ( all discussion in m3/h/m2 @ 50Pa ) https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=144#Comment_144 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=144#Comment_144 Fri, 02 Feb 2007 12:56:15 +0000 Paul in Montreal
From what I can tell 1.5ACH@50Pa is about the same as 3m^3/h/m^2 - if that's the case, then a figure of 10 as a target is dismal indeed. Over here, mechanical ventilation is mandated in the building codes so there's no excuse for leaky construction. If I recall correctly, R2000 certified construction requires a blower door test to be performed post-construction to verify the air tightness detailing. It's certainly not rocket science, though, as an estimated 70% of builders here can and do build to R2000 standards, whether or not the properties they build are R2000 certified. The new house we built was not R2000 certified - in fact, based on energy usage, we exceed R2000 standards by quite a bit (mainly due to the GSHP). Even the 109 year old house, post-renovation, exceeds R2000 energy usage standards, but is certainly not leak free (it measures 6.7ACH@50Pa - which I believe is still better than the target 10m^3/h/m^2 specified in the UK!)

Paul in Montreal]]> How tight is tight? ( all discussion in m3/h/m2 @ 50Pa ) https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=195#Comment_195 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11&Focus=195#Comment_195 Sun, 04 Feb 2007 09:27:46 +0000 tony
You are right about the target being dismal. Even funnier is that if the test fails then some attempt is made to do rectification then on retest it an automatic pass! Further only one building type needs to tested on an estate the rest are assumed to be just as leaky. They will for sure be leakier of course.]]>