Hi,
Does anyone know what happens when the BCA differs from the Australian Standard? Which one takes precedence?
Browse Forums Building Standards; Getting It Right! Re: BCA vs Australian Standard 2Oct 13, 2011 4:39 am The Harder You Try - the Luckier You Get ! Web site http://www.anewhouse.com.au Informative, Amusing, and Opinionated Blog - Over 600 posts on all aspects of building a new house. Re: BCA vs Australian Standard 7Oct 14, 2011 10:32 am The Harder You Try - the Luckier You Get ! Web site http://www.anewhouse.com.au Informative, Amusing, and Opinionated Blog - Over 600 posts on all aspects of building a new house. Re: BCA vs Australian Standard 15Oct 17, 2011 11:07 pm A thankful person is a happy person. [/color]My hobby design blog: http://aviewondesign.blogspot.com/ Re: BCA vs Australian Standard 19Nov 08, 2011 6:23 pm Hi all. Sorry for bumping up an old thread, but I thought it important to clarify a bit of confusion that seems to have crept in. ISSUE 1: Drawings for which Building Permit has been issued Under the WA and SA legislation that I am familiar with, it is an offence under the Act to undertake building works that are not in conformance with the plans approved by the local government authority. Thus if the Building Permit has been issued for drawings showing the membrane extending to ground level, this is how it must be installed. If the builder wishes to propose an alternative solution to the approved plans, then the revised plans need to be submitted to and approved by Council. I can't imagine that legislation in Victoria would be any different to this. ISSUE 2: BCA taking precedence over the Australian Standards The BCA does not take necessarily take precedence over the Australian Standards. Refer Part 1.0.7 (too long to reproduce here in full) which states that "(b) Where an acceptable construction manual and an acceptable construction practice contained in the same Part of Section 3 are deemed to satisfy the same component of a Performance Requirement, in order to comply with the Deemed-to-Satisfy Provisions it is only necessary to satisfy- (i) the appropriate construction manual; or (ii) the appropriate acceptable construction practice." In this instance, BCA Figure 3.2.2.3 relating to vapour barrier / DPM installation is part of an 'Acceptable construction practice'. See Part 3.2.1 which states that "Compliance with the acceptable construction practice contained in Parts 3.2.2 to 3.2.5 satisfies Performance Requirements P2.1 and P2.2.3 for footing and slabs..." The 'Acceptable construction manuals' relating to this Part are addressed just above in Part 3.2.0. This likewise states that "Performance Requirements P2.1 and P2.2.3 are satisfied for footings and slabs if they are installed in accordance with one of the following manuals: (a) The footing or slab is constructed in accordance with AS2870...". So referring back at Part 1.0.7, we see that both the acceptable construction manual (AS2870) and acceptable construction practice (Figure 3.2.2.3) satisfy the same Performance Requirements - and thus you only need to satisfy one of the two. As such the BCA detailing does not take precedence over AS2870. ISSUE 3: AS2870 compliance Termination of the vapour barrier at the inside edge of the footing is permitted by AS2870 Figure 5.2 "with local acceptance" and Clause 5.3.3.3(a) "where justified by satisfactory local experience". The question of "local exceptance" and "satisfactory local experience" is itself a legal minefield. WA has an interesting situation where the Builders' Registration Board has stated that termination of the vapour barrier at the edge of the footing is NOT permitted (June 2010 newsletter), but WA's largest residential consulting engineering firm (>40,000 footing designs since 1980) insists that in free-draining sands, this methodology has a history of satisfactory local experience. This one hasn't been played out through the courts yet, but I'm sure it's only a matter of time! Sorry if my reply is a tad long, but it's difficult to be more brief. Plus I enjoy digging into this stuff ![]() Re: BCA vs Australian Standard 20Nov 08, 2011 9:19 pm ![]() The question of "local exceptance" and "satisfactory local experience" is itself a legal minefield. WA has an interesting situation where the Builders' Registration Board has stated that termination of the vapour barrier at the edge of the footing is NOT permitted (June 2010 newsletter), but WA's largest residential consulting engineering firm (>40,000 footing designs since 1980) insists that in free-draining sands, this methodology has a history of satisfactory local experience. This one hasn't been played out through the courts yet, but I'm sure it's only a matter of time! ![]() ... but it's difficult to be more brief. Plus I enjoy digging into this stuff ![]() My signature is distracting people from my wise posts ... What we have done in a few theatres ( including my own) is run 2 layers of 13mm gyprock, but sounds insulation especially for the bass is really tricky as a lot of that… 4 2944 ![]() |