Structural and Non-Structural Defects Under the Building Act 2004 (ACT)

What it is

The Australian Capital Territory uses a two-tier warranty period under section 88 of the Building Act 2004 (ACT). Structural elements carry a 6 year warranty period from completion. Non-structural work carries a 2 year period. The classification does the work: a defect notified in year 3 is safe only if it goes to a structural element.

The Act does not carry a bright-line statutory definition of structural or non-structural. Access Canberra guidance and the Construction Occupations Registrar fill the gap, and ACAT applies the ordinary industry meaning in warranty disputes.

The section 88 split

Section 88 of the Building Act 2004 (ACT) implies five statutory warranties into every residential building work contract where the contract price is $12,000 or more. It then fixes the enforcement period at:

• 6 years after the day the work is completed, for structural elements
• 2 years after the day the work is completed, for non-structural work

The completion day is the later of the day the work is completed or the day the contract ends. Section 88 also provides that any contract term purporting to remove, restrict or limit the operation of the section is of no effect, so the periods cannot be shortened by contract.

Access Canberra's working definition of structural

Access Canberra guidance treats structural elements as including:

• foundations and footings
• load-bearing walls (internal and external)
• floor structure
• roof structure
• weatherproofing and external cladding on load-bearing components
• structural beams and columns

Non-structural work covers internal fitout, finishes, cabinetry, joinery, fixtures, non load-bearing internal walls and cosmetic finishes. The distinction is functional: does the element carry load, or does it enclose or finish the load-bearing structure.

That guidance is not statutory but Access Canberra applies it in complaint investigations. ACAT looks at the same test in warranty disputes and generally applies the ordinary industry meaning of structural: an element essential to the stability, integrity or load-bearing capacity of the building.

Weatherproofing sits in a grey zone

Weatherproofing is treated as structural where it is integral to the load-bearing external wall system (roof membrane, external cladding waterproofing, structural balcony waterproofing). It is treated as non-structural where the failure is confined to a fixture (a shower recess, a bathtub sealant, an internal wet-area membrane not affecting structural framing).

That is a distinction with practical consequences. A shower recess waterproofing failure notified in year 3 is out of time on the 2 year non-structural period. An external cladding waterproofing failure that has caused framing damage is inside the 6 year structural period. The characterisation drives the outcome.

No prescribed cladding or banned products rule

Unlike NSW (regulation 26A of the Home Building Regulation 2014 prescribes combustible cladding as a major defect) and the Building Products (Safety) Act 2017 (NSW) treatment of banned products, the ACT does not have a regulatory extension for combustible cladding or prescribed products under section 88. A combustible cladding failure is analysed on the ordinary structural test only.

Property Developers Act 2024 rectification orders

The Property Developers Act 2024 (ACT) added a separate rectification-order framework for developer-controlled residential projects. Rectification orders commenced 11 July 2024. That framework operates alongside section 88 rather than in place of it, and it uses its own defect categories with an emphasis on serious defects in class 2 buildings.

How the ACT compares

The ACT sits between NSW and QLD in the two-tier structure. NSW: 6 and 2 years, with a statutory major defect definition in section 18E(4) and prescribed cladding under regulation 26A. QLD: 6 and 1 years, no statutory structural definition. ACT: 6 and 2 years, no statutory structural definition. NT: 6 and 1 years.

The ACT's 2 year non-structural period is the longest of any two-tier jurisdiction outside NSW. That gives ACT owners a slightly wider window for cosmetic and fitout defects than QLD or NT allow, and matches NSW without the extensive prescribed-defect regulations.