Knockdown rebuild calculator
What would it cost to knock down and rebuild?
The build, demolition, approvals and a buffer for surprises, for the home you want on the block you already have. The numbers update as you go.
Your property
So it saves to the right property in your plan, and a builder can look at your block.
Home size
Storeys
Finish
How you'd pay for it
Value (optional)
Add both to see the equity change. The value after is your figure: check what new homes nearby have sold for.
What it's worth today
$
What it would be worth with the new home
$
More detail
Your block
While building (assumptions)
The interest rate is an assumption. A mortgage broker can tell you what applies to you.
What it costs
Build (220 m² at $2,500 to $3,200/m²)$550,000 to $704,000
Demolition$15,000 to $35,000
Council and approvals$8,000 to $15,000
Contingency (10% of the build)$55,000 to $70,400
Total, low to high$628,000 to $824,400
Middle estimate$726,200
Interest over 12 months (6.5%)$47,203
Total project cost$773,403
Your new home
Floor area220 m²
StoreysSingle
Footprint on the block220 m²
Bedrooms, bathrooms, garage4 / 2 / 2
FinishMedium
Before you start
These are indicative ranges. Site conditions, design and council requirements all move the numbers, so get at least three quotes from licensed builders.
Check what you can build (site coverage, height, setbacks)Builder or council
Approval pathway (it varies by state and council)Council or certifier
Survey, soil test and any trees or easementsSurveyor and builder
Disconnect services and arrange demolitionBuilder
Finance for the build, and where you live meanwhileMortgage broker
Insurance during the buildInsurer and builder