If you own a property in Perth with a large backyard, side access or simply more land than you need, you may have wondered: can I subdivide my block?
For some properties, the answer is relatively straightforward. For others, the land may appear large enough to subdivide but factors such as zoning, the position of the existing home, vehicle access, sewer infrastructure, easements or the shape of the site can significantly affect what is actually possible.
That is why the best place to start is not with a subdivision application. It is with a feasibility assessment of the property.
Understanding the site early can help determine whether subdivision is possible, what type of subdivision may work and whether the end result makes financial and practical sense before committing significant money to the project.
What determines whether a property can be subdivided?
There is no single test that determines whether a block can be subdivided. The property's zoning and Residential Density Code, or R-Code, are important starting points, but they are only part of the picture.
A proper subdivision assessment should also consider:
- the total site area and dimensions;
- the applicable R-Code and local planning requirements;
- the position and condition of the existing residence;
- whether the existing house is being retained or demolished;
- vehicle access to the proposed lots;
- sewer, water, power and other servicing requirements;
- easements and restrictions shown on the Certificate of Title;
- site levels, retaining and earthworks;
- existing trees and landscaping requirements;
- the likely configuration and usability of the resulting lots; and
- whether the development remains financially worthwhile once subdivision and construction costs are considered.
Two properties with exactly the same land area can therefore have completely different development potential.
Start with the R-Code
Most residential properties in Perth are assigned an R-Code such as R20, R25, R30 or R40. The R-Code provides standards including minimum and average site areas that help determine the potential residential density of the property.
Under the current R-Codes, for example, an R20 property generally has a minimum site area of 350m² and an average site area of 450m² per dwelling. R30 generally requires a minimum of 260m² and an average of 300m².
This means an uncomplicated R20 property will generally require around 900m² to create two lots while satisfying the current average-site-area requirement.
However, this should only ever be treated as a starting point. Local planning schemes, structure plans, dual density coding and site-specific circumstances can influence what may actually be permitted.
A 900m² R20 property is therefore not automatically a two-lot subdivision. Likewise, a property that initially appears unsuitable may have opportunities that aren't obvious without looking at the wider planning framework.
Is my block big enough to subdivide?
This is probably the most common question, but total land area alone doesn't tell the whole story.
Imagine two 900m² properties. The first is a wide corner block with an existing house positioned neatly toward one side. The second is a narrow property with the existing residence positioned through the centre of the site and limited access to the rear.
On paper they have the same area and the same R-Code. In practice, the first property may provide a straightforward subdivision opportunity while the second could require alterations to the existing house, demolition or an entirely different subdivision strategy.
That is why we generally look at usable development area, not simply the number shown on the title.
Can I keep my existing house and subdivide the backyard?
In many cases, yes. A retain-and-subdivide strategy can be an attractive option because the owner retains an existing dwelling while creating a new lot behind or alongside it. This is particularly common throughout established Perth suburbs.
However, the existing home needs to work with the proposed subdivision. Once a new boundary is introduced, issues such as setbacks, parking, vehicle access, outdoor living areas and the relationship between the existing house and new lot need to be considered.
Sometimes relatively minor modifications to the existing property can unlock a significantly better subdivision outcome. For example, removing an old garage, relocating parking or modifying part of an existing structure may create sufficient access to a rear lot.
In other situations, retaining the dwelling restricts the development so significantly that demolition and redevelopment become the stronger option.
A good feasibility assessment should compare those scenarios rather than assuming from the beginning that the existing house must either stay or go.
What is a battleaxe subdivision?
A battleaxe subdivision generally involves creating a lot behind another property, with the rear lot accessed via a driveway or access leg running from the street.
They are common throughout Perth because they can allow development of large backyards while retaining the original street-front residence.
However, access width, vehicle manoeuvring, servicing, existing buildings and the area allocated to the access leg all need to be considered.
A battleaxe configuration that technically fits on a survey does not necessarily mean it will produce a good building site. The eventual home still needs appropriate orientation, usable outdoor areas, parking, services and enough practical space to produce a desirable residence.
For that reason, we prefer to consider the likely future dwelling at the same time as the subdivision layout. It is much better to discover during feasibility that a proposed rear lot is difficult to develop than after the new title has already been created.
Services can have a major impact on subdivision costs
One of the less obvious parts of subdivision feasibility is understanding what will be required to service the new lots.
A subdivision may involve new or upgraded connections for sewer, water and electricity, along with drainage, crossovers, retaining walls, demolition, fencing and other site works.
The location of existing infrastructure can have a significant impact. For example, an existing sewer line or connection in an inconvenient location may alter the subdivision layout or create additional costs.
This is one of the reasons why a property can be technically subdividable but not necessarily financially attractive. A strong feasibility assessment should look beyond how many lots fit on the land and consider the likely cost of actually delivering them.
Do I apply to the local council for subdivision?
Subdivision applications in Western Australia are determined by the Western Australian Planning Commission (WAPC) rather than the local council.
Once an application is lodged, the WAPC can refer it to the relevant local government, utility providers and other authorities for comment before determining the application.
The local government therefore plays an important role, but it does not normally make the final subdivision decision.
A subdivision application generally requires a proposed subdivision plan, current Certificate of Title, landowner consent and relevant supporting information. Subdivision plans should be based on accurate and current survey information.
If approved, the WAPC will normally issue a conditional subdivision approval. Those conditions then need to be satisfied before the subdivision can progress through clearance, surveying and ultimately the creation of new titles.
Receiving WAPC approval is therefore an important milestone, but it isn't the end of the subdivision process.
What happens after subdivision approval?
Once conditional approval has been received, the project moves into what can often be the more involved part of subdivision: delivering the conditions.
Depending on the site, this can involve coordination between the owner, surveyor, local government, Water Corporation, Western Power, contractors and other consultants.
Required works are completed, relevant authorities clear their respective conditions, the survey documentation is finalised and the process eventually progresses through to Landgate for creation of the new titles.
This is why subdivision should be considered as a complete project rather than simply an application to the WAPC. The planning approval tells you that the subdivision can proceed subject to conditions. The next challenge is actually delivering it.
What are the proposed 2026 changes to R20 subdivision?
In July 2026, the State Government announced proposed reforms to the R-Codes, including the removal of the average lot size requirement for land coded R20 and below.
Under the proposal, some R20 properties of approximately 700m² could potentially be subdivided into two 350m² lots, compared with the approximately 900m² generally required under today's average-site-area requirement.
The State Government estimates that the change could potentially open subdivision opportunities for more than 50,000 existing residential properties across metropolitan Perth.
As at 13 October 2026, the R-Codes review remains underway. The WA Government expects proposed changes to be released for public consultation in late 2026. Subject to consultation, endorsement and approval, amendments are anticipated to begin taking effect from mid to late 2027.
Until then, development and subdivision applications continue to be assessed under the existing planning framework.
For owners of properties between approximately 700m² and 900m² in R20 areas, however, the review is certainly worth watching. A property that has limited subdivision potential today may look quite different if the proposed changes ultimately come into effect.
Is subdivision actually worth it?
Being able to subdivide and being worth subdividing are two different questions.
The highest possible lot yield isn't always the most profitable or practical outcome. Sometimes retaining an existing home and creating one additional lot provides the best balance between cost and return.
Another property may perform better if the existing home is removed and the site redeveloped as a duplex, triplex or grouped dwelling development.
There may also be situations where selling the newly created land produces a better result than constructing another residence - or vice versa.
This is where design and feasibility should work together.
That assessment should consider planning potential, construction requirements, subdivision costs, dwelling design, marketability and the owner's longer-term objectives.
How Shoreline Design can help
Shoreline Design can assist from the earliest stages of a subdivision project through to approvals and delivery.
We look at the property as a whole - considering the subdivision layout alongside the existing residence, future dwelling design, access, planning requirements and likely development constraints.
Where a project progresses, we can also coordinate the required consultants and assist throughout the subdivision and residential design process.
The aim is to establish a clear development strategy before significant money is committed.
This article is general information for Perth property owners. Planning rules, fees and costs change, and every property is different, so check the requirements for your own property before you act on it.