How much does a builder cost in Adelaide?
Adelaide builders quote either per square metre or per project. Single-storey extensions come in at $2,500–$5,000 for each square metre, and $3,500 is typical for standard finishes. Kitchens managed by a builder cost $20,000–$70,000, a bathroom $15,000–$45,000 and a turnkey granny flat $120,000–$250,000. Structural jobs come in lower: removing a load-bearing wall and installing a steel beam is $3,000–$15,000. Just over half of Adelaide homes have three bedrooms, a much bigger share than across Australia (ABS 2021 Census), so if you live in one, a fourth bedroom or a family room is exactly the kind of job the per-square-metre rate prices. All prices include GST.
Comparing cities, or after the Australia-wide picture? See the national guide: Builder cost in Australia.
Detailed Pricing — Building Cost in Adelaide 2026
| Service | Low | Typical | High |
|---|---|---|---|
| Minor structural repair (lintel, crack stitching, wall ties) | $500per job | $1,800 | $5,000 |
| Load-bearing wall removal + steel beam | $3,000per job | $8,000 | $15,000 |
| Pre-purchase building inspection / defect report | $400per job | $600 | $1,200 |
| Deck or pergola (builder-managed) | $5,000per project | $12,000 | $40,000 |
| Roofed patio / alfresco (builder-managed) | $12,000per project | $20,000 | $35,000 |
| Garage or carport (single to double) | $10,000per project | $25,000 | $55,000 |
| Bathroom renovation (builder-managed) | $15,000per project | $25,000 | $45,000 |
| Kitchen renovation (builder-managed) | $20,000per project | $35,000 | $70,000 |
| Single-storey extension (per sqm) | $2,500per sqm | $3,500 | $5,000 |
| New home build (per sqm, standard finish) | $1,600per sqm | $2,300 | $4,500 |
| Granny flat (1-2 bed, turnkey) | $120,000per build | $165,000 | $250,000 |
| Full home renovation (whole house) | $150,000per project | $300,000 | $600,000 |
| Second-storey addition | $250,000per project | $380,000 | $600,000 |
| Knock-down rebuild (3-4 bed, single storey) | $450,000per build | $650,000 | $1,000,000 |
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Get Adelaide quotes →Renovate, Extend or Rebuild in Adelaide?
In the Adelaide table, renovating the whole house is $150,000–$600,000, extending $2,500–$5,000 a square metre and rebuilding $450,000–$1,000,000. Building indemnity insurance is required on approved work costing $20,000 or more, covering defects up to $250,000 if the builder fails.
Common Building Projects and What They Cost
Home extensions
At $2,500–$5,000 a square metre, 30–50 m² is $75,000–$250,000.
Second-storey additions
A second storey: $250,000–$600,000.
Granny flats
A turnkey flat: $120,000–$250,000.
Knock-down rebuilds
Rebuild: $450,000–$1,000,000 — demolition is development needing approval.
Home Extensions and Second-Storey Additions in Adelaide
Since 10 November 2025, work under $20,000 is “minor domestic building work” with lighter rules, but every builder working for others must hold a contractor licence. Second storey: $250,000–$600,000.
Knock-Down Rebuild vs Renovation in Adelaide
In the City of Adelaide demolition is development, so it needs development approval first; heritage places carry stronger demolition controls. More than 10 m² of non-friable asbestos needs a Class B licence.
What's Included in a Builder's Quote
SA caps the deposit at $1,000 up to $20,000 and 5% above; you have five clear business days to terminate after signing. Minor structural repairs are $500–$5,000.
What Affects Builder Costs in Adelaide
A city of three-bedders
Adelaide has far more three-bedroom homes than the nation, 51.3% against 39%, and fewer with four or more (ABS 2021 Census). Adding a bedroom and ensuite to one of them costs $2,500–$5,000 a square metre. The typical rate sits above a new build at $1,600–$4,500, because every new room has to be tied into the old footings, roof and services.
Shared walls and tight access
Some 16.3% of Adelaide dwellings are semi-detached, terrace or townhouse homes, against 12.6% nationally (ABS 2021 Census). On these, a builder may be working beside a party wall with only a narrow side path, carrying materials through by hand. Opening up a living area by removing a load-bearing wall is $3,000–$15,000; the beam size and the temporary propping the engineer specifies decide whether your price sits low or high in that band.
Demolition counts as development
In South Australia, building work includes demolishing or removing a building, and development needs approval before it starts, though some minor work is excluded; your council can confirm which side of the line your job falls. Pulling down part of a house for an extension goes through the same system. Demolition controls are stronger again for State and Local Heritage Places, so check your property's listing before you pay for plans.
Building indemnity insurance
For domestic building work over $20,000 that needs development approval, an SA builder must hold building indemnity insurance and give you a copy of the certificate, and the work cannot begin without it. It covers defective work up to $250,000 if the builder dies, disappears or becomes insolvent. Owner-builders cannot buy this cover, a point to weigh before running your own extension to save the builder's margin.
Deposits, contracts and cooling-off
The deposit is capped at $1,000 where the work is up to $20,000, and at 5% of the price above that. On a typical granny flat, the deposit can be no more than $8,250. Any contract above $20,000 has to be written, carry the builder's licence number and be signed by both parties, and you then have 5 clear business days to terminate it.
Older homes and asbestos
An older house can hide asbestos in sheeting, eaves and wet areas, so have it identified before walls come down. SafeWork SA reserves non-friable removal above 10 square metres for Class B licence holders, and friable material for Class A. A defect report ($400–$1,200) shows what the old house needs, and repairs such as lintels or crack stitching run $500–$5,000.
Dry summers, wetter winters
The West Terrace station averages about 20 mm of rain in each of January and February, while June is the wettest month at 72.1 mm (BOM averages), so digging, pouring slabs and open-roof stages fit the dry months best. New rooms must also meet the insulation minimums for NCC climate zone 5, so check the quote includes them rather than leaving them for a variation.
How to Save Money on Building Cost in Adelaide
Frequently Asked Questions — Building Cost in Adelaide
Our Methodology
Prices on this page are compiled from publicly available cost guides, leading tradie marketplaces, peak industry body data, and individual tradesperson websites across Australia. We cross-reference ranges from multiple sources and adjust for city-specific cost differences. Our price guides are produced independently and no tradesperson can influence a published figure. All prices are estimates and will vary based on your specific job. Always get multiple quotes. Last reviewed June 2026. Read our full methodology →