BCA vs Australian Standard

Absolutely. My personal criteria is that I would only ever allow termination of the VB at the inside footing face in non-saline sandy soils where the soil profile is clean, free-draining sands to at least 1500mm deep and the area is not subject to a shallow water table. I've seen rising damp around perimeter walls in too many homes on supposed 'safe' foundation soils in Perth to do otherwise.

Perth builders would argue that this rising damp is pretty benign - and they're generally right, as far as the structure goes. It's not brick-eating high salinity rising damp like Adelaide experiences. But it's still a big ask in my opinion to expect home owners to cop ongoing plaster damage around the base of external walls just because the builder skimped on the vapour barrier.

I'd agree. It is just good building practice to ensure that the VB extends as far as possible.
We used to take great care to ensure that it was as free as possible from holes and then to extend it up past the outside of the slab and then fold it vertically up the side of the edgebeam up to 75mm below the first course of bricks.
We then used to seal the edges of the plastic to the concrete with waterproofing compound which you could paint if necessary.
Garden beds and side paths used to hide the plastic.
The 75mm clearance was for termite proofing.

Stewie

An update. The Building Commission has ruled that the BCA code must be followed and the builder will rectify the issue.

Good to hear a positive outcome =)

buildblue is absolutely correct.

It is important to understand the legislative hierarchy of it all;

1. The Building Act 1975 gives legislative authority to the BCA (at the time it was BCA 1996). The Building Act 1975 is cross-referenced with The Integrated Planning Act 1997, and The Standard Building Regulations 1993.
2. The BCA then uses a similar hierarchy system to implement the Guidance Level and Compliance Level - both of which has Australia standards referenced for further clarification and working implementation.
3. Within the Guidance Level, it states the objects and functional statements
4. Within the Compliance Level, it states the performance requirements and building solutions (and DtS provisions and alternative solutions within that).

So if there is a conflict between the BCA and the Australian standard, per The Standard Building Regulations 1993, Division 3 - BCA, Subsection 10 "for any subject matter with in BCA, any provision of an Australian Standard that also deals with the subject matter applies only so far as it epressly adopted by the BCA". In other words, if it is relative to the same topic and referenced, as long as it meetings the BCA DtS provisions then it is compliant and AS is superseeded respectively.

Sorry about the late response.

Agree totally re the legislative heirarchy, though obviously the Acts and Regulations vary from state to state.

Still don't agree that the BCA takes precedence over AS2870 though in this instance (VPM termination) even under the QLD Standard Building Regulations 1993 quoted. AS2870 is expressly adopted by the BCA as an appropriate construction manual for construction of footings and slabs (Cl. 3.2.0). Thus the provisions of AS2870 that deal with VPM termination are still valid, and the clause from Standard Building Regulations 1993 quoted does not state that BCA will take precedence in this instance.

I believe the intent of the clause you have quoted is prevent mis-interpretation of the BCA that may occur if non-explicitly adopted Standards are referenced. For example, it prevents you from directly applying the provisions and requirements of AS3600 Concrete structures to residential slabs and footings because the BCA explicitly references ONLY AS2870 and AS2159 for this section. This is vitally important because AS2870 contains some provisions that are "relaxed" compared to AS3600 (eg curing requirements), such that it actually states in AS2870 Section 1.2 "Residential footing system design and construction shall comply with AS3600 except that, where in conflict, this Standard shall take precedence."

So for that example, the clause from the Regulations would ensure that AS3600 cannot be called up directly in relation to the construction of a residential slab or footing. It can be called up indirectly, as AS2870 states that construction shall be in accordance with AS3600, but with the restriction that AS2870 shall take precedence where there is conflict. This allows the more relaxed curing provisions of AS2870 to be followed, and prevents building consultants from claiming that curing was not in accordance with AS3600.

this is interesting to know.

This was always my assumed understanding also. Although I must admit though I never looked up the exact wording of the subsection. I always thought it would be a little more along the lines of where an acceptable construction manual ie AS contradicts the BCA, the BCA takes precedence.

But it is worded in way that could be interpreted as Integrity mentioned. AS2870 is expressly called up to satisfy P2.1 and P2.3.3 in 3.2.0 as an acceptable construction manual. Which therefore meets the DTS provisions of 1.0.7 (b) in the same capacity as 3.2.2.6.

So effectively we have 2 different methods of acceptable construction expressly adopted by the BCA to meet the same performance provisions, which makes subsection 10 - as quoted above - invalid in this particular case. Would be interested to hear other peoples opinions.

That's the nuts and bolts of my interpretation. I have worked under South Australian and Western Australian legislation and neither of those contain any clause which would allow the BCA to take precedence over an Australian Standard where said Standard is an acceptable construction manual under the BCA, so I reckon it's pretty reasonable to assume that legislation in other states would be written in a similar vein. I also believe that careful reading of the wording of Qld Regs Subsection 10 supports my interpretation.

Always interesting reading and discussing other people's interpretations though

Australian Standards are documents developed by Standards Australia, a private company. Standards Australia is not a branch of Government. Many think that Australian Standards are legal documents but they are not unless the Standards have been mandated by Government. The use of Australian Standards is by choice unless mandated by Government.

A good discussion with some very interesting information.
From a builders perspective with thirty five years experience in NSW I always assumed the BCA was the highest level of compliance and the standards were a reference that it was based on.
'Appears not...
But then I'm only a humble carpenter.

Stewie

From a builders' perspective it's probably best to work to that view for the most part ... keeps you out of trouble with Council inspectors who don't understand otherwise

I come from an engineering perspective where I have in the past been able to justify construction that is not in accordance with the deemed-to-comply detailing of the BCA but that does comply with the "acceptable construction manual" referenced under the BCA. At that stage (things are built!) it's worth arguing, but from a new design and build perspective I'd normally recommend that the BCA be followed to avoid argument. It never hurts to be a tad conservative with some of these things.

I understand that there are elements of the BCA relating to glazing though that are less conservative than the referenced Standards, and that manufacturers typically follow the AS in this instance. I haven't had cause to check this out though.

Good advice Integrity.
I've only run into a couple of problems over the years and that's because of the customers decision which has come back to bite me on the arse.
Usually I defer to the engineer for anything structural and the rest I go with my experience and gut feel.
Knowing the tech side of the rules and regs and keeping up with the changes is always good practice though.

Stewie

Does HB39 have any legal standing in Victoria?

Does HB39 still have no legal standing in NSW or has this changed?

I agree with the sentiment expressed by Stewie D who posted...

"I always assumed the BCA was the highest level of compliance and the standards were a reference that it was based on.
'Appears not"

There is something wrong when a lesser AS can be called up to override a better BCA standard by using the "deemed to satisfy" provision. What is the point of hierarchy?

The whole situation of the BCA versus Australian Standard is a mess!

Look at the below and the chain of command

1. COAG is in charge (politians only & govt depts) Council of Australian Government!
2. ABCB (Australian Building Codes Board) runs or is the writing body for COAG - and is in charge of the NCC!
3. NCC is the National Construction Code which comprises the BCA & PCA!
4. BCA is the Building Code Australia.
5. PCA is the Plumbing Code of Australia!
6. The ABCB only came into existance in 1994 but was only validated this year in April 2012????
7. The ABCB comprises of two advisory committes - the BCC and the PCC!
8. The BCC is the Building Codes Committee
9. The PCC is the Plumbling Codes Committee
The BCC consists of:

ABCB Office (Chair)
A representative of the Australian Government
A representative of each of the State and Territory Governments
A representative of Local Government
Australasian Fire Authorities Council
Australian Institute of Architects
Australian Institute of Building
Australian Institute of Building Surveyors
Building Designers Association
Building Products Innovation Council
Commonwealth Scientific and Industrial Research Organisation
Consult Australia (Formerly ACEA)
Engineers Australia
Housing Industry Association
Master Builders Australia
Property Council of Australia
Standards Australia
New Zealand Department of Building and Housing (observer)
Building Research New Zealand Inc (observer)

The PCC consists of the following:

A senior representative of the ABCB (Chair)
A representative of the Australian Government
A representative of each of the State and Territory Governments
Air Conditioning and Mechanical Contractors Association
Association of Hydraulic Services Consultants Australia
Australasian Fire and Emergency Service Authorities Council
Australian Institute of Refrigeration Air-conditioning and Heating
Engineers Australia
Housing Industry Association
Master Builders Australia
Master Plumbers Australia
Plumbing Products Industry Group
Property Council of Australia
Standards Australia

So in theory we are all controlled by numerous advisory committees of COAG!!

There should be a NATIONAL Australian Standard on all of these areas!
The HB39 has been in revision by Australian Standards for nearly 8 years - nothing yet - so why are the revising it when it is not recognised!

Plumbing regulations are so open to different views that anything goes - especially in the roof and gutter industry!

Apologies for the lengthy reply - but frustration is the biggest thing for me in this industry regulation nightmare!

Some example simple questions?

Who exactly is the BCA?
Who exactly is the PCA?
Why is not the BCC and the BCA the same thing?
Why is not the PCC and the PCA the same thing?
Does Australian Standards (a private body?) have representation in COAG, BCA, NCC, PCA, PCC, BCC etc?
Why is this so complex?

Because it helps employment numbers looking good?

And that was just on regulations alone ... not to mention inspecting / enforcing how well are they being followed ...

Who says that the AS is lesser and the BCA is better

The BCA exists to act as a contractor's bible. It's there to provide methods by which a contractor can build a home that complies with all applicable regulations, and only have to fork out $300 a year or so for the privilege of having a copy of the BCA to work from.

The referenced Australian Standards are the documents on which the BCA is based, and they go into much greater detail on each topic and provide greater flexibility for design / construction. The difficulty is that you're looking at about $2500 a year to have access to all of them, and many of them are written for engineers (wholly or partially) rather than builders.

So the BCA is a simplified deemed-to-comply code that can be followed if you're building a simple house that fits within its framework. As soon as you want to do something a bit messy though that doesn't fall within the BCA, then you have to refer to the Australian Standards - that's usually when you'd get an engineer involved.

As such the ABCB haven't been able to make the BCA override the referenced Standards, as those Standards go into far more depth on their particular topics and allow designers flexibility to build structures which are outside of the scope of the simplified deemed-to-comply BCA rules.