Granny Flat FAQs

Granny flat costs in Perth range from $69,900 for a compact studio (28m²) to $160,000+ for a premium two-bedroom design (70m²). Our fixed-price packages include site works, council approvals, all connections, construction, premium inclusions, and a 7-year structural warranty. Book a free site assessment for an exact quote tailored to your block.

Not with us. Our fixed-price contracts are all-inclusive — design, approvals, site works, construction, utility connections, and handover. Be cautious of competitors quoting "build only" prices that don't include the $10,000–$30,000 in council fees, site preparation, and service connections. Always ask for a total cost that covers everything from first site visit to move-in keys.

Yes — the most common approach is accessing equity in your existing property through a refinance or construction loan. Many Perth homeowners find their property has enough equity to fund the entire build. We can refer you to specialist mortgage brokers who understand granny flat finance and can find you the best rate. Some lenders also offer specific "secondary dwelling" construction loan products.

Typically yes — by 15–25% according to Perth real estate data. A well-designed granny flat increases the property's rental income potential, which buyers value. In high-demand Perth suburbs, a quality secondary dwelling can add $150,000–$200,000 to your home's sale price, well above the cost of construction.

Yes. All secondary dwellings in Perth require at minimum a Building Permit from your local council. Depending on your R-Code zoning and local planning scheme, you may also need a Development Approval (DA). In many R20+ zones, granny flats up to 60m² can now be assessed as Permitted Development under simplified processes. We handle all approvals on your behalf — our 95% first-time approval rate is among Perth's best.

Council approval timelines vary: Building Permit only takes 4–6 weeks; Development Approval (DA) takes 6–12 weeks depending on the council. Some councils like City of Swan and Armadale have streamlined pathways for secondary dwellings. Our town planning team manages all applications, responds to council queries promptly, and pushes for fastest possible processing.

Under WA Residential Design Codes (R-Codes), secondary dwellings can typically be up to 60m² of habitable floor space. Some councils allow up to 70m² depending on lot size and zoning. The maximum also depends on your R-Code classification (R20, R25, R30, R40, R60 etc.), lot size, and total site coverage allowed. Our free site assessment will confirm the exact maximum for your specific property.

Secondary dwellings are generally permitted in R20 zones and above, subject to meeting lot size requirements (typically 450m²+ at R20). Higher density zones (R30, R40, R60) offer more flexibility on design and size. Some R-Code zones require a minimum lot size of 300m². Contact us for a free R-Code assessment — we'll tell you exactly what's possible on your block within 24 hours.

Setback requirements vary by R-Code zone and whether the granny flat is at the rear or side of the property. Typical setbacks: rear 3–6m, side 1–1.5m (at R-Code). Under new R-Code provisions, some rear setbacks can be reduced to 1m for lots over 350m². Our town planning team assesses setbacks as part of your free site assessment.

From our first site visit to key handover, the typical timeline is 16–22 weeks: Free site assessment and design (2–3 weeks), council approval (4–10 weeks), construction (8–12 weeks depending on size). We provide a firm construction timeline in your fixed-price contract and send weekly progress photos throughout the build.

No — you can remain in your home throughout the entire construction process. Our site setup is designed to minimise disruption, and we schedule noisy work during standard hours (7am–5pm weekdays). Access to your rear yard will be restricted during construction, but we work around your needs as much as possible.

Every granny flat we build comes with: a 7-year structural warranty (as required by WA law), a 12-month defect liability period during which we fix any issues at no charge, Home Indemnity Insurance (mandatory for projects over $20,000 in WA), and individual manufacturer warranties on all appliances. We stand behind every build.

Yes — renting out a granny flat is fully legal in Perth and extremely common. Your granny flat will be a separate tenancy with its own lease, bond, and rental agreement under the Residential Tenancies Act 1987. The only restriction is that in most zones, the owner of the property must reside on-site (either in the main home or the granny flat). We recommend consulting a property manager for specific tenancy advice.

Perth rental returns vary by suburb and design: Studios earn $350–$450/week, 1-bedroom designs earn $420–$520/week, 2-bedroom designs earn $500–$650/week. In premium inner-city suburbs (Fremantle, Subiaco, Mount Lawley), rents can exceed $700/week for a quality 2-bedroom granny flat. With Perth's vacancy rate below 1%, quality granny flats rarely sit vacant.

When rented out, granny flat costs can be depreciated and operating expenses (rates, insurance, maintenance, management fees, interest on finance) are tax-deductible. A quantity surveyor can prepare a depreciation schedule that often results in thousands in annual tax deductions. We strongly recommend consulting an accountant familiar with investment property. This is general information only — not financial advice.