An elite Sydney apartment building is being fitted with a second replacement of a terrace waterproof membrane, a mere five years after the replacement of the first membrane, which leaked from the time of completion.
The membranes were said to have complied with the National Construction Code (NCC).
But for more than a decade, owners and tenants residing beneath the terraces have tolerated mould-stricken walls, carpets and ceilings because the code fails to control waterproofing materials and methods.
Many governments and regulators believe that code compliance is the key to restoring public confidence in the market.
Yet more is needed, as was indicated in 2017, when the Building Ministers’ Forum–the collective of federal, state and territory ministers responsible for Australian building regulations–commissioned a report from Peter Shergold and Bronwyn Weir.
Their report indicated diminishing public confidence in the ability of the building and construction industry to produce safe, quality buildings.
And since that time, we have seen the structural failure and evacuation of Opal Tower on Christmas Eve 2018, the cladding fire at Neo200 in February 2019 and the structural failure and evacuation of Mascot Towers in June 2019.
Could the building code be part of the problem?
The National Construction Code started out as a minimum standard to guarantee a structure’s integrity and fire safety.
The code never was meant to supply meaningful control over all aspects of building work that render houses and multiresidential units liveable and durable. And the ethic of the minimum standard seems to apply.
The objectives listed on page 9 of volume 1 of the code, which concerns apartment units, are telling:
- ensure requirements have a rigorously tested rationale; and
- effectively and proportionally address applicable issues; and
- create benefits to society that outweigh costs; and
- consider non-regulatory alternatives; and
- consider the competitive effects of regulation; and
- not be unnecessarily restrictive.
In trying to contemplate “competitive effects”, to cease being “restrictive” and by promoting “non-regulatory alternatives”, such as self-certifying and self-regulating, the code has facilitated a sort of “anything goes” attitude in many aspects.
Waterproofing rules for houses and apartments, outlined in section F of the code, are seemingly insufficient.
The pertinent Australian Standards, AS 4654.1 and AS 4654.2, were composed with the participation of the building materials business.
The standards allow the usage of insufficient waterproofing membranes in a good number of building projects, especially those in which ceramic tiles are bonded to an unworkable liquid-applied membrane. This solution typically holds for fewer than five years.
Repairing these issues is costly and time-consuming, as it entails hacking up and replacing the tiles.
Also, each apartment building constructed sans a step in the slab at the junction separating walls and floors will develop leakage during a similar timespan.
Many experts believe that the building code could be enhanced by placing both class 1 (houses) and class 2 (apartments) structures in volume 2, which would be devoted to residences intended for sale.
Houses and apartments should be “fit for purpose” with a distinctly outlined objective to protect the purchaser. They should carry a required, government-enforced minimum statutory warranty of seven to ten years.
- The necessary durability of waterproofing membranes and requisites regarding all housing, class 2 apartments especially, must be explicitly outlined. Waterproofing should be regulated to hold for at least a 25-year period without substantial maintenance, and maybe for four decades for buildings in which access to the waterproofing element is in need of demolishing or is essentially complicated. Detailing that is not durable, such as slabs sans steps at wall junctions, or terrace and balcony tiles bonded to liquid-applied waterproof membranes, should be disallowed under the code.
- The structure of an apartment should sustain itself with no major maintenance for at least half a century. The minimum durability expectation for any envelope component and affiliated building finishes on buildings taller than three storeys should be 25 years, and maybe four decades for taller structures.
- The “performance requirements” of section F of the code, “Health and Amenity”, should be widened to guarantee that apartments are comfortable, cost-efficient and sustainable. Homes and apartments should be at all times “fit for purpose”.