Our Perth duplex permit application goes in around March 2027. Can we still elect NCC 2022, and what should we watch as the 1 May 2027 cutoff approaches?

Yes, a March 2027 application can still elect NCC 2022. The date that matters is when the building permit application is made, and every week of slippage towards May eats into a margin that disappears completely on 1 May 2027. [1] [2]

How the option actually works. WA does not run a fixed "either edition" window in the way some states do. Regulation 31A(2) of the Building Regulations 2012 sets the applicable building standards as the technical requirements in either: [1]

• (a) the edition of the Building Code in effect at the time the permit application is made; or
• (b) the edition that was in effect 12 months before the application is made.

That second limb is a rolling look-back, and it is the whole answer to your question. WA adopted NCC 2025 on 1 May 2026. [2] For a March 2027 application, 12 months earlier is March 2026, when NCC 2022 (Amendments 1 and 2) was still the edition in effect. So you can choose NCC 2025 under (a) or NCC 2022 under (b). [1] [2]

For any application made on or after 1 May 2027, the look-back lands on or after 1 May 2026, when NCC 2025 was already in effect. Both limbs then point to NCC 2025, which is why it becomes the sole edition for permit applications from that date. [2]

It is an option, not a default. The 12-month rule does not apply itself automatically. If you want NCC 2022, elect it positively in the application and make sure your building surveyor's certificate of design compliance is prepared on that basis. [2] The regulation frames the choice as one edition or the other, so plan to nominate a single edition for the whole permit rather than mixing provisions. [1]

What to watch as the cutoff approaches:

• Lodgement date, not design date or approval date. The test runs off when the application is made. [1] A design finished in February counts for nothing if the application goes in on 3 May.
• "Around March" is roughly four to eight weeks of margin. Consultant reports, engineering and energy ratings are the usual reasons a lodgement slides. If anything is likely to run late, lock the lodgement date first and build the programme back from 30 April 2027.
• Re-lodgement is the hidden risk. A fresh application carries its own date. If an application is withdrawn and re-made after 30 April 2027, the NCC 2022 option will not be there for it. The regulation text does not address how later amendments to an existing permit are treated, so if you expect design changes after lodgement, get your surveyor's position on that in writing.
• (2A) is not a trap for you. Subregulation (2A) limits the look-back to applications made on or before 30 April 2021 or on or after 1 July 2021. [1] That carve-out was for the 2021 transition and does not affect a 2027 lodgement.

If you land on NCC 2025 instead. WA adopted NCC 2025 with its own modifications: the livable housing provisions and separate NatHERS load limits remain disapplied in WA. [2] Both matter for a duplex, so check the WA position before assuming the national NCC 2025 text applies in full.

The regulation text quoted here is the compilation as at 1 May 2021. The Building Amendment Regulations (No.2) 2026 (SL 2026/44) adopted NCC 2025, and the adoption position confirms the 12-month applicant option still operates to 30 April 2027. [2] With a hard date this close, confirm the current wording with Building and Energy (now part of LGIRS) or your building surveyor before relying on it.