Home Extension in Cairns.Know what it should cost in Cairns.
Tailored to the Cairns, QLD market — local pricing adjustment applied automatically. A few quick questions, no obligation.
A typical home extension in Cairns costs between $102,600 and $345,600 in 2026, with most projects landing around $194,400.
Last reviewed:
Where is the project?
Enter your postcode so we can apply local pricing.
- LocationCairns
- What type of extension?Ground-floor rear extension
- Approximate extension size (m²)40 m²
- What finish level are you planning?Standard
- When are you hoping to start?In 3–6 months
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.
Home Extension in Cairns.
Cairns pricing tends to be higher than Brisbane due to freight costs, humidity-driven material specs, and cyclone compliance.
Frequently asked questions
How much does a home extension cost in Cairns?
In Cairns, a typical home extension costs between $102,600 and $345,600 in 2026, with most projects landing around $194,400. Pricing varies with size, finish level, complexity and your specific site.
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.
Related calculators
Estimate the cost of a whole-house renovation — multiple rooms, structural changes, kitchen and bathrooms.
Estimate the cost of a kitchen renovation in Australia — from a flat-pack refresh to a fully custom design with stone and integrated appliances.
Detailed estimate for a typical Australian bathroom renovation, from a basic refresh to a full strip-out and rebuild.
Estimate the cost of replacing or restoring your roof — Colorbond, concrete tile or terracotta.