Why Build Behind?
The smart way to grow your property portfolio without selling.
Keep Your Home
Retain and continue living in your existing home throughout and after the development.
Unlock Hidden Value
Your backyard may be sitting on significant untapped development potential.
Sell or Rent
Sell the rear dwelling for a profit or retain it as an investment property for ongoing income.
Low Disruption
Construction occurs behind your home — typically minimal impact on daily living.
How a Build Behind Works
A build-behind development involves subdividing your block to create a new rear lot, then constructing a second dwelling accessed via a right-of-way or battleaxe driveway. Your existing home remains on its own title at the front.
These projects are particularly popular in inner and middle-ring suburbs where large blocks are common. Typical build-behind projects cost $350,000–$700,000 for the new dwelling, plus subdivision costs.
Build Behind FAQs
How deep does my block need to be?
A minimum block depth of around 40–50 metres is generally needed to accommodate a build-behind development, allowing for the existing home, a shared driveway, and a new rear dwelling with appropriate setbacks.
What is a battleaxe block?
A battleaxe block is a rear lot accessed via a narrow strip of land (the "handle") that connects to the street. The new dwelling sits on the "blade" at the rear. This is the most common configuration for build-behind developments.
How long does a build-behind take?
Allow 18–24 months from feasibility to completion — approximately 3–6 months for approvals and 10–14 months for construction of the new dwelling, running alongside subdivision processes.