Some properties are just not suitable for a backyard subdivision.

One solution to develop such properties maybe to demolish all or part of the existing house. However, this action might be commercially unviable.

If you have a mortgage, your lender will prefer you not demolish the existing house unless of course it requires a significant amount of upkeep or other works.

So why can’t you subdivide some backyards?

The number one reason is size and more importantly depth of the backyard.

The backyard will need to satisfy multiple planning requirements; most of which might be news to you!

They are at the least:


Typical properties will need to accommodate car parking for both the existing house and the new unit ( townhouse) in the backyard.

Councils prefer all parking be kept out of sight in the front yard. They also discourage parking in front of the facade of the existing house

Generally speaking, Councils want front yards dedicated to landscaping.

The 3m wide driveway to service the parking in the backyard can take up a lot of land.

The parking spaces chew up the backyard too!

( A 3 bedroom house require 2 cars with one space under cover like garage or carport

A 2 bedroom unit needs one car space)

Secluded Open space

Think of these as private secure courtyards. They range in size and depends on the zoning,

It can vary between 20sqm and 80sqm. The most common size is 25 sqm. with a minimum dimension of 3m ( 3×8.3 sqm or 6×4.1sqm etc). There goes another chunk of the backyard!In some suburbs, this space can be a balcony, if the unit has living on the upper level and bedrooms on the ground. Most councils are not in favour of such reverse living designs.

Aspect and over shadowing

A north facing backyard is better for energy efficiency and has less shadowing impact on the neighbouring backyards. Both these items matter to Council.

A property with a north facing front  or side boundary might create shadows on the property behind it for most of the day.

Aspect or orientation as it is commonly known can also impact the size of the secluded open space.


Trees play a role in design and building footprint. If the tree is in the neighbour’s land, the new dwelling’s foundations must not adversely impact on that tree’s health.

If the  mature and larger trees are on your land and are “protected” by a planning instrument like a Vegetation Overlay (VPO) then the new dwelling must not impact on the root system more than the allowable 10% amount. Trees have roots which spread a fair distance if it is a mature tree.


Easements are areas on the land dedicated to carry services like the sewer, stormwater drains and so on. One cannot build fixed structures on an easement.

Some easements might carry no services. To build on it, one requires consent from the Statutory Authorities.

Single storey in backyards

Some councils have a fixed rule that only single storey buildings can be developed in the backyard. They call it “protecting the backyardscape!”

That could mean a very small second dwelling which might not stack up commercially.


Some property titles have a covenant attached to it. Most covenants are manageable. However, one type commonly called a “single dwelling covenant” means exactly that. The land cannot have more than a single dwelling!

Removing the covenant can be expensive and success is not guaranteed for all properties.

Subdivision costs

Irrespective of the size of the new unit in the backyard, there are fixed development costs which could discourage some property developers.

These costs include, but are not limited to, the fees to the authorities ( council is one, Titles office to register the new titles another), architect or designers fees, town planner’s fees, land surveyors’ fees, other relevant consultants fees, the cost to connect services ( sewer, water drainage, power, NBN etc) to the backyard and other fixed costs and reports if applicable.

Subdivision fees and costs could be around the $30,000 plus mark for a typical dual occupancy subivision. Then add the cost of constructing the new townhouse and any modifications to the existing house to meet Council’s planning requirements.

At the end of the day, you are subdividing to build equity or make a profit.

In inner city areas, small backyards sell for big dollars. Mid and outer ring suburbs of Melbourne are the opposite.

Do the costs justify development?

Location of driveway

To develop the backyard, a 3m wide driveway must be built from the front boundary to the backyard to accommodate the carport or garages. In some instances, turning bay areas may be required. This requirement chews up developable space.Measure the distance from side of house to side fence (assuming it is on the boundary). That distance must measure minimum 3m and better to be higher.

The above items  are just some of factors one must consider if thinking of subdividing the backyard.

By Swarup Dutta

Swarup Dutta, AuArchitecture‘s Founder, is a Registered Planner and affiliated with the Australian Institute of Architects, Planning Institute of Australia and Victorian Planning and Environmental Law Association. While consulting to real estate developers and Architects he managed over 250 planning permits in Victoria.