Can neighbours appeal an approved dual-occupancy DA?

Yes, in some circumstances. A neighbour who made a representation during the DA notification period may be able to apply to the ACT Civil and Administrative Tribunal (ACAT) for review of an approved or conditionally approved dual-occupancy DA if the decision may cause them material detriment. A person who had a reasonable excuse for not making a representation may also have review rights in some circumstances.

However, not every dual-occupancy approval can be appealed by a neighbour. The Planning Act 2023 contains specific matters that are exempt from third-party ACAT review. The Notice of Decision should therefore be checked to confirm whether review rights apply to the particular DA.

Where a third-party ACAT review right applies, the application generally must be lodged within 20 working days of receiving the decision.

Reference: ACT planning Amend or appeal an application - https://www.planning.act.gov.au/applications-and-assessments/development-applications/amend-or-appeal-an-application