How are setbacks measured on an irregular boundary?
On an irregular-shaped block, the setback is measured horizontally from the relevant block boundary to the outside face of the building or structure. Because an irregular boundary may change direction, the setback needs to be checked against the actual surveyed boundary at the relevant location, rather than assuming one uniform measurement across the site.
The setback follows the actual shape of the boundary. If the boundary is angled, curved or changes direction, you measure the distance from that boundary to the building at the relevant points.
This means an irregular block can have different setback distances at different points along the same building, particularly where the building and boundary are not parallel.
Example: If a side boundary angles toward the house, the setback becomes smaller as the boundary gets closer. The design therefore needs to be checked at the point where the building is closest to that boundary.
A registered surveyor establishes the accurate block boundaries so that the proposed building can be correctly positioned and its setbacks checked. ACT Planning specifically states that survey information is used to ensure development complies with building setback requirements.
Reference: Territory Plan 2023 | Notifiable instruments
Link on the answer: https://www.legislation.act.gov.au/ni/2023-540/Current
Where this question is kept
| Dual Occupancy Q&A | #500 | agrees | 28/08/2026 |