The WA Residential Design Codes Explained: A Plain-English Guide for Small Developers
The R-Codes are the foundation of residential planning in Western Australia, but most small developers encounter them only through the filter of a refusal or a condition they didn't see coming. This is the guide that avoids both.
This is not a substitute for professional planning advice on your specific project. It is a plain-English orientation to the framework, the parts that matter most for small-scale residential development across the Southwest.
What the R-Codes are and where they sit
The Residential Design Codes (State Planning Policy 7.3, Volumes 1 and 2) are a state government policy document that sets development standards for all residential land in WA. They are given legal effect through each council's Local Planning Scheme, which adopts them as the applicable residential development standard.
Volume 1 covers single houses, grouped dwellings (duplexes, townhouses), and multiple dwellings up to three storeys. Volume 2 (the Medium Density Housing Code, introduced in 2023) applies to specific medium-density development types in designated areas. For most small Southwest developers, Volume 1 is the operative document.
The R-Codes set a state-level floor. Local Planning Policies (LPPs) adopted by individual councils can impose additional or modified requirements above that floor, and in many Southwest councils, they do.
The density coding system
Every residential lot in WA carries an R-Code density designation — R10, R15, R20, R25, R30, R40, R60, R80, and so on. The number represents an approximate dwelling yield per hectare.
The density coding determines:
• Minimum lot size per dwelling — at R20, the minimum is 350m² average (300m² minimum). At R30, it's 260m² average. At R40, it's 200m² average. These minimums determine theoretical development yield from a given lot area.
• Minimum lot frontage — minimum frontage requirements apply at each density level. Lots below minimum frontage cannot be subdivided regardless of area.
• Street setbacks — front setback distances vary by density code and street type.
Important: R-Code density sets a theoretical ceiling on development yield. Site constraints, setback requirements, outdoor living area provisions, and parking requirements all reduce what's actually achievable. A 700m² R20 lot 'theoretically' supports two dwellings. Whether a compliant design actually fits requires a full feasibility assessment, not just a calculation.
Deemed-to-comply versus design principles — the most important concept
Every R-Code standard is structured around two tiers:
• Deemed-to-comply standard — meet this and the standard is automatically satisfied. No further justification is required.
• Design principle — the intent the standard is trying to achieve. If you can't meet the deemed-to-comply standard, you can propose an alternative solution that achieves the design principle. This requires council assessment and is not automatically approved.
For small developers, this matters because the R-Codes are not a binary pass/fail system. There is genuine design flexibility, but exercising it requires clear justification and some councils are more receptive than others. Knowing which standards you need to meet versus which you can argue around is a significant part of development feasibility work.
The standards that most affect small developers
Setbacks
Front, rear, and side setbacks create the buildable envelope. For grouped dwellings, setbacks apply not only from external lot boundaries but also from the internal boundary between individual dwellings. These internal setbacks are not zero, typically 1.0m, and they affect how closely individual dwellings can be positioned on a shared site.
Outdoor living areas
Each dwelling must have a primary outdoor living area meeting minimum area and dimension requirements. For a two-bedroom dwelling, the minimum is typically 24m² with a 4m minimum dimension. The area must be directly accessible from a main habitable room, receive at least one hour of direct sun on the winter solstice, and have reasonable visual privacy.
On compact lots, fitting compliant outdoor living areas for each dwelling while also meeting setbacks, parking, and landscaping requirements is frequently the binding design constraint on yield, more so than minimum lot size.
Parking
One bay per dwelling for one or two bedrooms; two bays for three or more bedrooms. On narrow lots, accommodating two independent parking bays without driveways dominating the street frontage requires deliberate design. Tandem parking (one behind the other) is generally permitted but reduces the independent usability of the second bay.
Open space
The R-Codes prescribe minimum open space ratios, the proportion of the lot that must remain unbuilt (driveways, parking, and roofed structures excluded). At R30, the typical open space requirement is 45%. On a 700m² lot, 315m² must be unbuilt. This is less constraining than it sounds on larger lots but becomes significant on compact infill sites.
Overlooking and visual privacy
Active habitable room windows must maintain minimum setback distances from adjoining lots to limit direct overlooking. The required setback varies by window size and floor level. Where the setback can't be met, screening, sill height adjustment, or obscure glazing must be applied. In grouped dwelling development, overlooking provisions apply between the dwellings as well as to external boundaries, a common source of design conflict on tight sites.
The layer above the R-Codes: local planning policies
Individual councils can adopt Local Planning Policies that impose additional requirements. Examples in the Southwest:
• City of Bunbury — has LPPs covering medium-density design and specific street character requirements in established suburbs.
• Shire of Busselton — has policies covering design in coastal townsite areas, tourist accommodation, and vegetation clearing that affect development siting.
• Shire of Augusta-Margaret River — has an active design review focus with policies covering materials, colours, and building character in tourist and coastal areas.
• Shire of Capel and Shire of Dardanup — have rural residential policies that overlay standard R-Code provisions with minimum lot sizes and use restrictions not in the state code.
The R-Codes set the floor. Local policies can, and often do, raise the bar significantly above it. Always check the local planning scheme before finalising a development brief.
Frequently Asked Questions
What is the difference between grouped housing and multiple dwellings under the R-Codes?
Grouped dwellings are two or more dwellings on the same lot, each with their own private outdoor area at ground level. They include duplexes, townhouses, and villas. Multiple dwellings are buildings containing two or more dwellings where not all have private outdoor areas at ground level, apartments and units above ground floor are the typical examples. Different R-Code standards apply to each type.
What does R-Code density mean for a 700m² lot in Bunbury?
In the City of Bunbury, R20 is the most common density coding in established suburbs. At R20, the minimum average lot size per dwelling is 350m², so a 700m² lot supports a theoretical yield of two dwellings. Whether a compliant design fits, meeting setbacks, parking, outdoor living, and open space requirements, requires a proper feasibility assessment. The R-Code density tells you the theoretical maximum, not the guaranteed outcome.
Can a council refuse a development that complies with the R-Codes?
If a development fully complies with the deemed-to-comply standards, refusal is difficult to sustain, but not impossible where local planning policies impose additional requirements. Where design principle arguments are being used (i.e., you're not meeting deemed-to-comply), the council has genuine discretion. For investor-developers, deemed-to-comply compliance is the most secure path to approval.
Running a feasibility on a South West development site? We carry out R-Code and local planning scheme assessments as the starting point for every project — send us your lot number for an initial read at fastlane.drafting@gmail.com
