“How much for a granny flat?” might be the question I’m asked most — and it has the most misleading answers on the internet. You’ll see granny flats advertised from under $40,000, and you’ll meet people who spent $250,000. Both numbers are real. They’re just not describing the same thing.
The honest 2026 answer: a finished, council-approved, move-in-ready granny flat on the Gold Coast typically costs between $130,000 and $250,000, depending on size, specification and your site. Here’s the full breakdown — what the advertised prices include, what they leave out, and where the money actually goes.
A complete turnkey granny flat on the Gold Coast costs $130,000 to $250,000 in 2026 for most projects — designed, built, connected and certified. Construction typically runs around $1,800 to $3,500+ per square metre, with small builds sitting toward the higher rates because the expensive rooms — kitchen and bathroom — don’t shrink with the floor plan.
If that’s higher than the prices you’ve seen advertised, keep reading — the gap has an explanation, and understanding it will save you from the most common granny flat budgeting mistake.
Every project is different, but homeowners usually want a planning figure before deciding whether to investigate further:
| Granny flat size | Typical turnkey range | Typical use |
|---|---|---|
| Studio (~35–45m²) | $80,000 – $140,000 | One person; home office + guest space |
| One bedroom (~45–60m²) | $120,000 – $200,000 | Parent or adult child; rental |
| Two bedroom (~60–80m²) | $180,000 – $280,000 | Couple or small family; strongest rental appeal |
Treat these as planning ranges, not quotes — the same floor plan can move tens of thousands of dollars depending on your block. Site conditions, access, services and finishes do the moving, and that’s exactly what a proper feasibility check prices before you commit.
Granny flat pricing comes in three very different flavours, and advertising rarely says which one you’re looking at:
Kit or base price. The structural package — frame, roof, cladding, windows and doors. This is where “from $37,500”-style advertised prices usually live. No slab, no site works, no plumbing or electrical, no approvals, no kitchen or bathroom, no connection to services. It’s a real price for part of a building.
Lock-up. The shell erected and weatherproof on your slab. Still no fit-out, services or certification.
Turnkey. A finished, certified dwelling you can live in — which is what almost everyone actually means when they ask “how much for a granny flat?”
None of these flavours is dishonest — but comparing a kit price against a turnkey quote is comparing a box of parts to a home. One of the biggest budgeting mistakes I see is exactly this: a family anchors on a kit price, commits, and then discovers the slab, services, fit-out and certification cost more than the kit did. When you compare quotes, compare what’s excluded: site preparation, foundations, service connections, approvals, certifier fees and insurance are where a cheap headline number quietly doubles.
For a typical turnkey project, the spend breaks down roughly like this (2026 planning ranges):
| Where it goes | Typical range | The thing people miss |
|---|---|---|
| Building shell (frame, roof, cladding, windows) | $70,000 – $150,000 | The advertised “kit price” usually stops here |
| Internal fit-out (kitchen, bathroom, lining, flooring, electrical) | $30,000 – $90,000 | The most underestimated line — wet areas are expensive at any size |
| Site works & service connections (earthworks, slab, water, sewer, power) | $20,000 – $90,000 | Varies the most block to block |
| Design, approvals & certification | from ~$5,000 combined | The small slice that protects every other dollar |
Having priced builds for thirty years — as the designer and as the builder — the pattern is consistent: it’s rarely the shell that blows a granny flat budget; it’s the site works nobody scoped and the fit-out nobody itemised. Sloping sites, difficult access, tree removal and long service runs all show up here — which is why two identical granny flats two streets apart can differ by $40,000.
Plan on roughly $2,000 to $10,000+ across building approval, private certifier fees, inspections and permits, depending on your site and the approval pathway. Most Gold Coast granny flats proceed as secondary dwellings through building approval rather than a full development application — the rules that decide which pathway applies (and the size and siting limits that come with it) are covered in my granny flat rules guide.
One line item to check early: council infrastructure charges. Some Queensland councils levy them on secondary dwellings and some exempt them, and positions change — I’ve seen this single line item surprise owners mid-project more than any other, which is why we confirm the current Gold Coast treatment as part of feasibility rather than assuming it.
Design and documentation for a granny flat is the small slice that protects every other dollar — a design matched to your block’s conditions, drawn for approval and priced for buildability. My design fees start from $3,000, and because I hold both a building designer’s and a builder’s licence, the plans you get are ones a builder can actually price and build without surprises. If you’re weighing a granny flat against other options for your block, my feasibility guide to duplexes and dual living walks through the decision, and my cost to build guide gives you the wider Gold Coast cost picture.
Queensland allows secondary dwellings to be rented, which changed the maths for a lot of Gold Coast homeowners — a well-designed two-bedroom granny flat in the right suburb can be a genuine income asset, as well as housing family. But the honest version of the investment case has conditions: the block has to suit it (access, siting, drainage), the build quality has to justify the rent, and the total cost — not the advertised price — has to make the yield work. A $180,000 turnkey granny flat earning solid rent can be a strong result; the same building squeezed onto the wrong block, or a cheap build that rents poorly, is not. That’s a feasibility question before it’s a construction question.
If the investment case is what you’re weighing, everything turns on one thing: your block’s real numbers, not the planning ranges above. Everything in this guide is useful for deciding whether to explore further — and useless for a contract. The real number comes from your block: its slope, services, access, overlays and what the design needs to do. That’s what the first stage of my process establishes — feasibility, realistic cost range and design direction, before you’re committed to anything.
Request a consultation and we’ll work out what a granny flat would actually cost on your block. Consultations are paid — and the fee is credited toward your design fee if you proceed. Design fees from $3,000.
How much does a 60m² granny flat cost on the Gold Coast?
As a 2026 planning range: roughly $150,000–$220,000 turnkey, depending on specification and site conditions. Site works and services are the biggest variables.
How much does an 80m² granny flat cost?
An 80m² two-bedroom granny flat — the largest size generally permitted as a secondary dwelling — typically runs $200,000–$280,000 turnkey on the Gold Coast in 2026. Bigger floor plate, but the kitchen and bathroom cost the same, so the per-square-metre rate improves.
Why are some granny flats advertised from under $40,000?
Those are typically kit or base prices — the structural package only, without slab, site works, fit-out, services, approvals or certification. A finished, approved dwelling costs a multiple of the kit price.
What does council approval cost for a granny flat?
Typically around $2,000–$10,000+ across building approval, certifier fees, inspections and permits, depending on the site and pathway. Check infrastructure charges for your council early — treatment varies.
Can I rent out a granny flat on the Gold Coast?
Queensland permits secondary dwellings to be rented. The rules about size, siting and approval that make a granny flat legal are covered in my granny flat rules guide.
What’s the cheapest way to build a granny flat?
Honestly: the cheapest good way is a design matched to your block — avoiding over-excavation, long service runs and mid-build changes. Chasing the lowest advertised price usually costs more by completion.
Is a granny flat a good investment on the Gold Coast?
It can be — Queensland permits secondary dwellings to be rented, and a well-designed two-bedroom flat in the right suburb can earn solid rent. But the maths only works on the TOTAL cost (not the advertised price), on a block that genuinely suits it, at a build quality that justifies the rent. That’s a feasibility question before it’s an investment decision.
How long does a granny flat take to build?
Once approved, most site-built granny flats take around 3–6 months on site, depending on weather, site complexity and builder availability. Design and approval time comes before that.
David Steadman
Licensed Builder & Building Designer
David Steadman is the founder of Design Science, a Gold Coast building design practice backed by over 30 years of hands-on construction experience. One of few Australians holding both a QBCC Builder's Licence and Building Designer licence, David brings a rare combination of design thinking and practical building knowledge to every project.
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