Questions & Answers

Can an approved dual occupancy design be changed later?

Under s 31 of the Building Act 2004, an owner may apply to the certifier for approval of amended building plans after Building Approval has been issued.

Under s 32, the certifier may approve the amended plans only where the statutory requirements are satisfied, including that the building resulting from the amended plans would not be significantly different from the building shown in the original approved plans.

Where the proposed change also means that the development is no longer covered by its existing Development Approval, an amendment to the DA may be required under the Planning Act 2023.

Reference Building Act 2004 (ACT204-11) – ss 31–32 – https://www.legislation.act.gov.au/View/a/2004-11/current/html/2004-11.html

Last reviewed: 14 September 2026 Information current as at: 15 September 2026

Short Answer

Changes may be approved by the building certifier if the resulting building is not significantly different from the original approved plans and the other requirements are met. If the changes are no longer covered by the existing DA, a DA amendment may also be required.

Detailed Explanation

Under s 31 of the Building Act 2004, an owner may apply to the certifier for approval of amended building plans after Building Approval has been issued.

Under s 32, the certifier may approve the amended plans only where the statutory requirements are satisfied, including that the building resulting from the amended plans would not be significantly different from the building shown in the original approved plans.

Where the proposed change also means that the development is no longer covered by its existing Development Approval, an amendment to the DA may be required under the Planning Act 2023.

Key Point

No minimum block size does not remove the need for planning assessment.

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