How much does a granny flat cost in Adelaide?
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A turnkey studio or one-bedroom granny flat in Adelaide costs $110,000–$160,000, typically $130,000, and a two-bedroom unit $140,000–$210,000. A factory-built one-bedroom module delivered to the block is $80,000–$120,000, before it is connected and finished on site. Most Adelaide dwellings are detached houses, the kind of site a granny flat goes beside, but South Australia sets limits on what counts as one, and approval, site preparation and services are often quoted apart from the build itself. Measured by floor area, a turnkey build comes to $2,300–$3,500 per square metre. All figures include GST.
Comparing cities, or after the Australia-wide picture? See the national guide: How much does a granny flat cost in Australia?
Detailed Pricing — Granny Flat Cost in Adelaide 2026
| Service | Low | Typical | High |
|---|---|---|---|
| Prefab / modular granny flat — 1-bed (delivered) | $80,000total | $95,000 | $120,000 |
| Studio / 1-bed granny flat (35-45m², turnkey) | $110,000total | $130,000 | $160,000 |
| 2-bed granny flat (~60m², turnkey) | $140,000total | $175,000 | $210,000 |
| Custom / premium 2-bed (high-end finishes) | $210,000total | $260,000 | $320,000 |
| Two-storey granny flat (complete, incl. site costs + approvals) | $280,000total | $345,000 | $425,000 |
| Granny flat with attached single garage (complete, incl. site costs + approvals) | $170,000total | $210,000 | $260,000 |
| Garage / outbuilding conversion | $40,000total | $75,000 | $120,000 |
| Turnkey build (per m² built) | $2,300/sqm | $2,800 | $3,500 |
| Site works + service connections | $15,000total | $25,000 | $40,000 |
| Development approval + building consent | $3,000total | $5,000 | $11,000 |
| Demolition / site clearing (if needed) | $3,000total | $6,000 | $15,000 |
| Driveway, path & basic landscaping | $5,000total | $10,000 | $20,000 |
| Privacy fencing (per m) | $80/m | $130 | $190 |
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Get Adelaide quotes →Prices include GST. Based on Adelaide metro area, October 2026. Outer suburbs may vary.
Adelaide’s Granny Flat Market in 2026
South Australia calls it ancillary accommodation: on the same site as an existing house, with no more than two bedrooms, and it needs development approval — planning and building consent. Building without approval risks a maximum penalty of $120,000.
There are no restrictions on who can live in it, and approval conditions can’t stop it being rented. On a vacant lot it isn’t ancillary accommodation: it would most likely be assessed as a dwelling. The table’s development approval and building consent row is $3,000–$11,000.
In the Adelaide table one bedroom or a studio is $110,000–$160,000 turnkey and two bedrooms $140,000–$210,000.
How Granny Flat Costs Vary Across Adelaide
Eastern Suburbs
Typical cost: $180k–$330k turnkey
Norwood, Burnside, Unley, Kensington. Heritage villas and premium finishes. Rear blocks can be tight; budgets often match the quality of the main home.
Coastal
Typical cost: $160k–$300k turnkey
Glenelg, Henley Beach, Brighton, Semaphore. Beachside blocks with strong rental demand. Detached 2-bed builds are popular; coastal detailing adds a little cost.
Adelaide Hills
Typical cost: $150k–$280k turnkey
Stirling, Aldgate, Mount Barker, Crafers. Large blocks suit bigger builds; bushfire-prone areas need BAL-rated construction.
Northern Suburbs
Typical cost: $120k–$230k turnkey
Salisbury, Elizabeth, Mawson Lakes, Gawler. The most affordable area — flat blocks and easy access keep turnkey prices low. Among the best yields in Adelaide.
Southern Suburbs
Typical cost: $120k–$230k turnkey
Marion, Morphett Vale, Aberfoyle Park, Noarlunga. Established and growth suburbs on generally flat land. Standard single-storey and prefab builds dominate.
What You’ll Actually Pay — Common Adelaide Granny Flat Builds
Adelaide granny flats, priced from this page.
1-bedroom granny flat — 40m², turnkey
$110,000–$160,000 total
A one-bedroom at the typical $130,000, plus the typical development approval ($5,000): $135,000.
2-bedroom granny flat — 60m², turnkey
$140,000–$210,000 total
Two bedrooms is the most SA allows; the typical turnkey price is $175,000.
Prefab / modular 2-bed — installed
$80,000–$120,000 delivered (1-bed row)
The only prefab row: a one-bedroom delivered, $80,000–$120,000.
Garage / outbuilding conversion to studio
$40,000–$120,000 total
A garage conversion is $40,000–$120,000 and needs development approval like a new build.
Custom architect 2-bed / two-storey
$210,000–$425,000 total
Custom two-bedroom $210,000–$320,000; two-storey or with a garage $280,000–$425,000 — still two bedrooms at most.
Granny flat prices in Adelaide (2026): 1 bedroom, 2 bedroom, prefab and turnkey
A granny flat in Adelaide costs $110,000–$160,000 for a 1-bedroom or studio of 35–45 m² built turnkey, with $130,000 typical, and $140,000–$210,000 for a 2-bedroom flat of around 60 m². Turnkey means designed, approved, built, connected and finished to move into. Per square metre built, that is $2,300–$3,500. A 1-bedroom prefab or modular flat is $80,000–$120,000 delivered, before the slab, services and finishing on site.
| Job | Low | Typical | High |
|---|---|---|---|
| Studio / 1-bed granny flat (35–45 m², turnkey) | $110,000 | $130,000 | $160,000 |
| 2-bed granny flat (~60 m², turnkey) | $140,000 | $175,000 | $210,000 |
| Prefab / modular granny flat, 1-bed (delivered) | $80,000 | $95,000 | $120,000 |
| Turnkey build (per m² built) | $2,300/m² | $2,800 | $3,500 |
| Site works + service connections | $15,000 | $25,000 | $40,000 |
| Garage / outbuilding conversion | $40,000 | $75,000 | $120,000 |
1 bedroom vs 2 bedroom granny flat prices in Adelaide: the second bedroom adds floor area, a longer roof and more wall, so the price moves with the square metres rather than the room count; the per-m² figure above is the way to compare two quotes of different sizes. What does not scale is the fixed cost: site works and service connections ($15,000–$40,000) are much the same for a 1-bed and a 2-bed, which is why the smaller flat is dearer per square metre.
Kit vs turnkey: a kit price is the building supplied, not built. Add the slab, the trades to erect and fit it out, the service connections and the approval before comparing it with a turnkey price. Converting an existing garage ($40,000–$120,000) is the cheapest route to a self-contained flat where the structure is sound.
What moves a granny flat quote in Adelaide:
- Size and layout: square metres set the build price; a bathroom and kitchen are the dearest rooms per metre.
- Site: sloping blocks, poor soil, tree removal and long runs to the sewer, water and power all sit in site works.
- Approval: South Australian rules on size, setbacks and who can live in the flat decide whether it is a simple approval or a full application.
- Finish: standard fittings and finishes are the base; stone benchtops, premium tapware and timber floors move a build toward the custom band.
- Access: a tight side access limits machinery and prefab delivery, adding labour.
Ask every Adelaide builder for the same thing: a turnkey price, the square metres, and site works and approvals as separate lines, so the price list from each compares.
What Affects Granny Flat Costs in Adelaide
What SA counts as a granny flat
South Australia calls it ancillary accommodation: it sits on the same site as an existing home, may be self-contained, and has no more than two bedrooms, and PlanSA's fact sheet sets the size at 60 m² at most, with shared utilities and no subdivision. People searching for a three-bedroom price should know that design falls outside the definition. A two-bedroom turnkey unit within it is $140,000–$210,000.
Approval before the slab
Building ancillary accommodation needs development approval under the Planning, Development and Infrastructure Act, covering both planning and building consent, because it is a Class 1a habitable building under the National Construction Code. Applications are decided by a relevant authority such as the council, an assessment panel or an accredited professional. Budget $3,000–$11,000 for approval; building without it risks a maximum penalty of $120,000.
Site works and services
Site works and service connections add $15,000–$40,000 to the build, and clearing an old shed or structure first is $3,000–$15,000. Water, sewer, power and stormwater all have to reach the new unit, so every metre between the granny flat's wet areas and the house's existing lines costs money. A sloping or rocky block, or narrow side access for machinery, pushes the site figure toward the top.
Building through the seasons
June is Adelaide's wettest month at 72.1 mm, while January and February average about 20 mm each and January tops out at 28.7 °C on average (BOM averages). Earthworks and slabs go best on dry ground, so lodging in autumn can line a pour up for the drier months. Adelaide is in NCC climate zone 5: eaves, insulation and window placement for summer heat cost little to settle at the drawing stage.
Family now, tenant later
SA approval conditions cannot stop ancillary accommodation being leased, rented or occupied by anyone, so a unit built for a parent can later be let. At the ABS 2021 Census the median rent across Adelaide was $320 a week, and 28.4% of households rented. A unit with its own path and a private yard is easier to let; a dividing fence is $80–$190 per metre and the driveway, path and basic landscaping $5,000–$20,000.
Insurance, deposit and contract
Where domestic building work is over $20,000 and needs development approval, an SA builder must hold building indemnity insurance and give you a copy of the certificate, and work cannot start until it is in place. The contract must be in writing, the deposit is capped at 5% of the value, and you have 5 clear business days after signing to terminate. Every turnkey build in our table is well past that $20,000 line.
Prefab, conversion or two storeys
A delivered prefab at $80,000–$120,000 costs less than a site-built studio at the typical price, though site works, connections and approval still come on top. Converting an existing garage or outbuilding is $40,000–$120,000, depending on the plumbing it needs. At the top end, a complete two-storey unit is $280,000–$425,000 and a two-bedroom with high-end finishes $210,000–$320,000.
How to Save Money on Granny Flat Cost in Adelaide
Frequently Asked Questions — Granny Flat Cost in Adelaide
Our Methodology
The prices on this page are compiled from publicly available cost guides, leading tradie marketplaces, peak industry body data, and individual builder websites across Australia. We cross-reference ranges from several sources and adjust for city-specific cost differences using advertised rates, wage data, and cost-of-living indicators. Our guides are produced independently — no tradesperson can influence a published figure. All prices are estimates and vary with your specific job, so always get multiple quotes. Last reviewed October 2026. Read our full methodology →