WA Residential Design Codes: R-Codes for residential design control

What it is

The Residential Design Codes (R-Codes) are the statewide planning rules that control most residential design in Western Australia. They sit under State Planning Policy 7.3 and are administered by the Department of Planning, Lands and Heritage (DPLH) with local councils. The R-Codes apply to single houses, grouped dwellings, multiple dwellings and most ancillary residential development. Volume 1 covers low to medium density (codes R5 through R60 with rules extending up to R80 in some contexts). Volume 2 covers apartments at R30 and above.

Every residential lot in WA carries a density code on the local planning scheme map. The code is the starting point for any feasibility check. It controls how many dwellings can fit on a site, how far they must sit from boundaries, how much of the site can be hard surface and how much open space must remain.

How density codes work

A density code is a ratio of lots to land area. R20 means one dwelling per roughly 450 square metres on average. R30 reduces that to around 300 square metres. R40 sits near 220 square metres. R60 and above push into apartment territory. R5 to R12.5 cover rural-residential and large-lot suburbs where average lot sizes run between 800 and 2,000 square metres.

The codes set both a minimum site area per dwelling and an average site area per dwelling. The Local Government uses both figures when reviewing a subdivision or development application.

Setbacks

The R-Codes specify a primary street setback (the front boundary to the closest part of the dwelling), a secondary street setback (for corner lots) and side and rear setbacks tied to the wall height and length. Lots coded R20 and above can attract a 50 per cent primary street setback reduction where the front area lost is compensated by additional open space deeper into the lot.

Plot ratio and site cover

Higher density codes from R40 up apply a plot ratio limit (the ratio of total floor area to site area). Lower density codes rely on site cover (the percentage of the lot occupied by the building footprint) and open space requirements. The intent is the same: stop overbuilding on small lots.

Open space

Open space is a mandatory percentage of the site that must remain unbuilt. The deemed-to-comply percentage rises as density rises in some categories and falls in others, so the code must always be read alongside the council's local planning policy.

2026 update

The current R-Codes Volume 1 took effect in April 2026. From 10 April 2026, in areas covered by a structure plan or local development plan, the previous transitional provisions ended. Single-house developments at R50 and above are now assessed against Part C of Volume 1. Builders quoting an existing-conditions site at R50 or above should confirm the assessment pathway with the council before lodging a development approval.

How TradeLens uses this

TradeLens reads the density code from the development application or the local government planning scheme and checks the proposed dwelling against the deemed-to-comply setback, plot ratio and open space figures. Where the proposed design needs a variation through the design principles pathway, TradeLens flags the matter for early surveyor or planning consultant review. The risk is real. A design principles assessment can add weeks to approval and may attract neighbour submissions that derail the project.

Common pitfalls

• Reading the local planning scheme code without checking whether the area has a structure plan or LDP overlay. Overlays can change the operative density.
• Assuming a 50 per cent primary street setback reduction is automatic. It is conditional on the open space trade-off being shown on the plans.
• Building a boundary wall longer than the wall-on-boundary limit for the code. R20-R25 allow walls up to 3.5 metres in height for limited lengths. R30-R40 allow more length. Going over the limit triggers a design principles assessment.
• Treating Volume 2 apartment rules as optional for R30 sites. Where the proposal is an apartment, Volume 2 applies regardless of preference.

What to do

Pull the density code from the local planning scheme before any design work. Build a quick deemed-to-comply test for setback, plot ratio, site cover and open space. If the design needs a variation, raise it as a risk on the quote and price the extra approval time. Confirm whether the lot sits inside a structure plan, an activity centre or a precinct that modifies the base R-Code.