1 and 2 bedroom granny flat prices in Perth
A 1 bedroom or studio granny flat in Perth is $110,000–$160,000 built turnkey in our Perth table, typically $130,000, and a 2 bedroom of around 60 m² is $140,000–$210,000, typically $175,000. Our table lists site works and the building permit as separate rows, and the all-in totals below add them to the build.
1 and 2 bedroom granny flat prices in Perth (2026)
| Job | Perth range (our table) | Typical |
|---|---|---|
| Prefab / modular 1 bedroom (delivered) | $80,000–$120,000 | $95,000 |
| Studio / 1 bedroom, 35–45 m² (turnkey) | $110,000–$160,000 | $130,000 |
| 2 bedroom, around 60 m² (turnkey) | $140,000–$210,000 | $175,000 |
| Custom / premium 2 bedroom (high-end finishes) | $210,000–$320,000 | $260,000 |
| Site works + service connections | $15,000–$40,000 | $25,000 |
| Building permit + R-Codes assessment | $3,000–$11,000 | $6,000 |
Rows from our Perth granny flat table. Demolition, a driveway, landscaping and fencing are separate rows there if your site needs them.
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Three all-in totals for a Perth 1 or 2 bedroom flat
The build price is only part of the bill. Each total below adds site works and the building permit to one of the build rows, all at their typical figures.
| All-in build | Rows used (typical) | All-in at the typicals |
|---|---|---|
| Prefab 1 bedroom | $95,000 build + $25,000 site works + $6,000 permit | $126,000 |
| Turnkey 1 bedroom (35–45 m²) | $130,000 build + $25,000 site works + $6,000 permit | $161,000 |
| Turnkey 2 bedroom (around 60 m²) | $175,000 build + $25,000 site works + $6,000 permit | $206,000 |
Each total adds the typical figures of the rows named in our Perth granny flat table. If a builder's turnkey price already includes site works or the permit, don't add them twice; demolition, a driveway or landscaping would be extra.
What the second bedroom adds
At the typical figures, the second bedroom adds $45,000 to the build ($175,000 against $130,000), while site works cost much the same for either size. A custom 2 bedroom with high-end finishes runs $210,000–$320,000 in our Perth table.
Prefab or built on site?
A prefab or modular flat is built off site and delivered, so the slab, the service connections and finishing on site sit outside its price. A turnkey build is done on your block. Compare the two on an all-in basis, as in the totals above, rather than on the headline price.
Getting 1 and 2 bedroom quotes you can line up
Ask each builder for the floor area in square metres, the build price, and site works and the building permit as separate lines. That makes a 1 bedroom quote and a 2 bedroom quote comparable, and shows straight away if a turnkey price already covers the site costs.
Frequently asked questions
How much does a 1 bedroom granny flat cost in Perth?
A turnkey studio or 1 bedroom of 35–45 m² is $110,000–$160,000 in our Perth table, typically $130,000. A prefab 1 bedroom is $80,000–$120,000 delivered. Site works and the building permit are separate rows on top.
How much does a 2 bedroom granny flat cost in Perth?
A turnkey 2 bedroom of around 60 m² is $140,000–$210,000 in our Perth table, typically $175,000, and a custom 2 bedroom with high-end finishes $210,000–$320,000. Site works and the building permit are separate rows on top.
Is a prefab 1 bedroom granny flat cheaper than building on site?
On the headline price, yes: a prefab 1 bedroom is $95,000 typical delivered in our Perth table against $130,000 for a turnkey 1 bedroom. The delivered price is before the slab, service connections and finishing on site, so compare the two all-in.
What do site works and the permit add?
Site works and service connections are $15,000–$40,000 in our Perth table, typically $25,000, and the building permit with the R-Codes assessment $3,000–$11,000, typically $6,000. Site works cost much the same for a 1 bedroom or a 2 bedroom flat.
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