Dual occupancy rules in Stirling
Building a dual occupancy in Stirling? City of Stirling applies the Western Australia planning framework. Here's what that means locally — plus the overlays worth checking on your specific block.
Driven by your R-code density - most R20 lots need about 900 m²
It comes down to your R-code. Two dwellings on one lot are grouped dwellings under the Residential Design Codes, and the density code mapped to your lot - R20, R30, R40 and so on - sets the average and minimum site area per dwelling, which is what decides whether your block can take two.
Key rules at a glance
| Site area per dwelling | Set by your R-code. Indicative figures: R20 average 450 m² and minimum 350 m²; R25 average 350 m² and minimum 300 m²; R30 average 300 m² and minimum 260 m²; R40 average 220 m² and minimum 180 m². |
| What that means for two dwellings | Roughly 900 m² at R20, 700 m² at R25, 600 m² at R30 and 440 m² at R40 (indicative - the average site area applies across the whole lot). |
| Density code | Mapped per property by the local planning scheme. Split codes such as R20/R40 apply in some areas and can unlock a higher density where the scheme criteria are met. |
| Approval pathway | Development approval from the local council in most cases, assessed against the R-Codes, plus WAPC approval for any subdivision or survey-strata. |
| Can it be subdivided or strata titled? | Yes. Green title subdivision creates fully independent lots; survey-strata is used where a driveway or services are shared. Both are approved by the WAPC, generally within 90 days, then conditions must be cleared before new titles issue. |
| Typical timeframe | Commonly 2-4 months for development approval, plus around 90 days for WAPC subdivision approval and further time to clear conditions and create titles. |
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.
Dual occupancys in Stirling
City of Stirling is the authority for Stirling in Perth. The statewide Western 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 dual occupancy in Stirling?
Usually yes. In Western Australia, a dual occupancy generally needs an application, and City of Stirling 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 Stirling?
City of Stirling is the consent authority for Stirling (Perth). You can review local planning controls on the council website and lodge through your state planning portal.
What size block do I need for a duplex in Perth?
Divide the lot area by the average site area for your R-code. At R20, where the average is 450 m² per dwelling, you generally need about 900 m²; at R30 (average 300 m²) about 600 m²; at R40 (average 220 m²) about 440 m². If your lot falls under the average needed for two dwellings it will not support a duplex unless a split code or a specific scheme provision applies.
Sources
- Residential Design Codes Volume 1 (including Medium Density) - WA Government ↗
- Revised R-Codes now in effect - Department of Planning, Lands and Heritage ↗
Related building rules
General guidance only — not professional planning advice. Local requirements in Stirling can differ from the statewide summary and change over time; always confirm with City of Stirling before starting work. Last reviewed: July 2026.
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