Designing for Small and Narrow Lots in WA: Making the Most of Every Square Metre
A compact block doesn't have to mean a compromised home. But it does require a completely different design approach, one that starts with the planning constraints, not the floor plan.
As land prices rise across the Southwest and infill development becomes more common, designing for smaller and narrower lots has become a core part of our work. The planning framework, the design strategies, and the common mistakes are all quite specific to this lot type.
The planning framework for small lots
In WA, the Residential Design Codes (R-Codes) and the Medium Density Housing Standards govern small lot development. Key provisions include minimum setbacks, lot boundary wall provisions, outdoor living area requirements, and open space ratios. In the Southwest, local planning policies layer additional requirements on top, in some councils, minimum lot frontages and streetscape requirements significantly affect what can be built.
A narrow lot in WA is generally one under 10m frontage. Small lots are typically under 300m², though the relevant threshold varies by zone. Both categories trigger planning provisions that don't apply to standard lots.
Design strategies that work on small lots
• Orientation before everything else - on a narrow lot, the orientation of the long axis determines passive solar potential. A north-south narrow lot is far more workable than an east-west narrow lot. Understand what you're working with before briefing a designer.
• Go up, not out - two-storey design is often the most cost-effective way to deliver floor area on a compact site while meeting outdoor living and open space requirements.
• Open plan on the ground floor - open plan living allows natural light to reach the interior of a narrow plan and makes spaces feel larger than their footprint.
• Integrate the alfresco into the plan - on a tight lot, the outdoor living area needs to be designed as part of the floor plan, not added to the side of it.
• Minimise corridor space - in a compact home, every square metre of corridor is a square metre that could be a room. Direct access layouts reduce waste.
• Built-in storage throughout - built-in storage in every bedroom and living area prevents clutter and maintains liveability in a smaller footprint.
Common mistakes on small lots
The most common mistake is treating a small lot the same as a standard lot - just with less room. The result is typically a house that sits poorly on the site, has inadequate natural light, and fails one or more planning requirements.
Specific traps include underestimating the size of the required outdoor living area (and therefore underestimating how much of the lot it consumes), not accounting for the turning radius of a car on a small driveway, and designing rooms at the minimum NCC dimensions without considering furniture layout.
Frequently Asked Questions
What is the minimum lot size for a house in WA?
Minimum lot sizes depend on the R-Code density of your zone. At R20 (common in established suburbs), the minimum lot size for a single dwelling is 350m² with an average of 450m². At R40, the minimum is 200m². Check the density coding for your specific lot.
Can I build two dwellings on a narrow lot?
It depends on the lot size, frontage, and density coding. Two dwellings on a narrow lot require each dwelling to meet setback, outdoor living, and parking requirements independently, which significantly constrains the minimum lot width. For lots under 10m frontage, two-lot development is generally very constrained.
Do I need a development application for a house on a small lot?
In most cases, a small lot house can be assessed under the deemed-to-comply provisions of the R-Codes without a full development application. However, if the design requires any design principal departures (non-standard setbacks, wall heights, etc.), a development application is required.
Got a small or narrow lot and not sure what's possible? Get a feasibility check from us first at fastlane.drafting@gmail.com
