Granny Flats rules in Onkaparinga
Building a granny flat in Onkaparinga? City of Onkaparinga applies the South Australia planning framework. Here's what that means locally — plus the overlays worth checking on your specific block.
Approval needed, but a fast-track path exists
Yes. Ancillary accommodation of up to 70 m² is allowed on the same allotment as your house. Planning and building approval are always required, but a streamlined deemed-to-satisfy pathway applies where the design meets the Code.
Key rules at a glance
| Maximum floor area | 70 m² (raised from 60 m² in Nov 2024) |
| Bedrooms | Commonly capped at 2 (check your zone) |
| Minimum site area | Varies by zone |
| Approval type | Development approval (deemed-to-satisfy path available) |
| Can it be rented? | Yes - to anyone |
| Self-contained | Allowed (own kitchen, bathroom, laundry) |
Heritage, flood and bushfire controls on your specific lot can remove the fast-track and require a full application — even when the general rules say you're fine.
Granny flats in Onkaparinga
City of Onkaparinga is the authority for Onkaparinga in Southern Adelaide. The statewide South Australia rules above set the baseline; the council can apply extra local controls, and heritage, flood or bushfire overlays on your lot can change what's allowed.
Frequently asked questions
Do I need council approval for a granny flat in Onkaparinga?
Usually yes. In South Australia, a granny flat generally needs an application, and City of Onkaparinga is the authority that assesses it. See the full state rules for the pathway and what's required.
Which council approves a granny flat in Onkaparinga?
City of Onkaparinga is the consent authority for Onkaparinga (Southern Adelaide). You can review local planning controls on the council website and lodge through your state planning portal.
How big can an ancillary dwelling be in South Australia?
Up to 70 m², increased from 60 m² by a November 2024 change to the Planning and Design Code.
Sources
- Unpacking rules for ancillary accommodation - PlanSA ↗
- Ancillary accommodation, caravans and moveable housing FAQ - PlanSA ↗
Related building rules
General guidance only — not professional planning advice. Local requirements in Onkaparinga can differ from the statewide summary and change over time; always confirm with City of Onkaparinga before starting work. Last reviewed: July 2026.
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