Home Extension.Know what it should cost.
A few quick questions — no obligation, no spam. Your estimate updates as you go.
A typical home extension in Australia costs between $95,000 and $320,000 in 2026, with most projects landing around $180,000.
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Where is the project?
Enter your postcode so we can apply local pricing.
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What goes into the number.
We start from a per-m² extension rate, scale by extension type, finish and site complexity, then add fixed inclusions like new bathrooms or kitchens.
- Extension size in square metres and whether it's ground floor or up.
- Type of build — a second-storey addition requires structural reinforcement of the lower level.
- Site conditions — slope, access, soil class and overlays.
- Whether the extension contains a wet area or new kitchen.
- Design fees, council approvals, BASIX/NatHERS energy compliance.
Frequently asked questions
How long does a home extension take?
Design and approvals typically take 4–8 months. Construction is 4–9 months depending on size and complexity. Most projects from idea to finish run 12–18 months.
Is a second-storey addition cheaper than building a new home?
Not necessarily. The per-m² rate is often higher than a ground-floor extension or a new build, because you're reinforcing the lower level and working with existing services.
What's NOT included in the estimate?
Major site works (rock excavation, retaining walls), demolition beyond the extension footprint, soft landscaping, and furniture/appliances. Design fees are budgeted but final architect / draftsperson fees vary.
See local pricing for your city
Each city page includes a local pricing adjustment, assumptions and FAQs.
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