Dual occupancy rules in Onkaparinga
Building a dual occupancy 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.
Allowed in most residential zones, subject to site area and frontage per dwelling
Often yes. The Planning and Design Code treats two homes on one allotment as semi-detached dwellings, a group dwelling or a residential flat building, and each zone sets a minimum site area and frontage per dwelling - so the zone and the numbers mapped to your allotment decide it.
Key rules at a glance
| Minimum site area per dwelling | In the General Neighbourhood Zone the deemed-to-satisfy figure is 300 m² per semi-detached dwelling, 250 m² per row dwelling, and 300 m² average (including common areas) for group dwellings (indicative - the Code sets it per zone and Technical and Numeric Variations mapped to your allotment override it). |
| Minimum frontage per dwelling | In the General Neighbourhood Zone, 9 m per semi-detached dwelling, 7 m averaged for row dwellings, and 15 m of total site frontage for group dwellings (indicative - varies by zone and TNV). |
| Zones permitted | The General Neighbourhood, Suburban Neighbourhood, Housing Diversity Neighbourhood, Urban Neighbourhood and Established Neighbourhood zones commonly envisage semi-detached or group dwellings - check the zone mapped to your allotment. |
| Approval pathway | Deemed-to-satisfy consent from an accredited professional or council where the criteria are met, otherwise performance assessed by the council. |
| Can it be subdivided or community titled? | Two dwellings can sit on one title with just planning and building consent. Creating separate titles needs a further land division consent - Torrens where the allotments are fully independent, or community title where a driveway, services or common area is shared. |
| Typical timeframe | Often a few weeks for a deemed-to-satisfy assessment; commonly 2-4 months when performance assessed and notified. |
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.
How often this applies in Onkaparinga
These are the overlays that can remove the fast-track, measured across every parcel in Onkaparinga from the same data behind our zoning map. They describe the council, not your block, and they are counted separately — one parcel can carry more than one, so they cannot be added together.
| Overlay | Share of parcels | What that means here |
|---|---|---|
| Heritage | 3.15% | 2,688 parcels flagged. The rest are mapped and sit outside it. |
| Flood | 75.55% | 64,472 parcels flagged. The rest are mapped and sit outside it. |
| Bushfire | 55.5% | 47,366 parcels flagged. The rest are mapped and sit outside it. |
The most common zone in Onkaparinga is General Neighbourhood, covering 48.8% of its 85,342 parcels. What you can build is decided by your own lot's zone, not the council's most common one.
Measured from our mapped parcel data, snapshot taken 2026-08-12. Overlays are checked live for a specific address on the address tool.
Dual occupancys 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.
Visit City of Onkaparinga ↗ Full South Australia rules →
See the Onkaparinga zoning map → — every parcel in Onkaparinga by zone, lot size and mapped constraints.
Frequently asked questions
Do I need council approval for a dual occupancy in Onkaparinga?
Usually yes. In South Australia, a dual occupancy 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 dual occupancy 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.
What size block do I need for two houses in Adelaide?
It depends on the zone and the Technical and Numeric Variation mapped to your allotment. In the General Neighbourhood Zone the deemed-to-satisfy figures are 300 m² of site area and 9 m of frontage per semi-detached dwelling, so about 600 m² and 18 m of frontage for two. Look your allotment up on SAPPA to see the exact figures that apply, because a Technical and Numeric Variation can change them.
Sources
- Planning and Design Code - PlanSA ↗
- Guide to the Planning and Design Code (PDF) - PlanSA ↗
- South Australian Property and Planning Atlas (SAPPA) ↗
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.
Talk to a town planner in Onkaparinga
This page covers the general rules. A qualified town planner can tell you what applies to your actual block — the zone, the overlays and the approval path — before you spend money on drawings.
- Qualified, practising town planners
- Advice on your property, not a generic rule
- No cost, no obligation