The Australian Granny Flat Guides & Costs Hub
Your questions, answered. From council approvals and construction costs to design inspiration and DIY tips, our guides help you navigate every step.
Quick answer: Start with costs and council rules for your state, then compare designs and suppliers. A granny flat project lives or dies on a realistic budget and a clear grasp of the approval process: construction costs have stabilised, but council fees keep rising in Victoria and New South Wales.
- Costs first: use the cost calculator before you talk to builders.
- Rules vary by state: NSW CDC vs DA, Victoria Part 5 exemptions and Queensland certifier pathways differ.
- Design affects approval: setbacks, height and floor area limits change what councils will sign off.
Which Guide Should You Start With?
Costs & Finance
Construction & Materials
Steel versus timber frames, roofing choices and slab requirements explained in plain English.
Explore constructionRegulations
State rules, setbacks and permit guides so you know what your council will and will not approve.
Explore regulationsRules by state
Compare size limits, approval pathways and rental rules for every Australian state in one table.
Open state hubDesigns & Ideas
What Should You Know Before You Budget?
Kit price is not the finished price
Multiply the kit price by roughly 2.5 to 3 to reach your real move-in cost. A $30,000 kit usually finishes at $75,000 to $90,000 once trades, slab and fit-out are done.
Stay under the approval threshold
Across New South Wales, Victoria and Western Australia, keeping under 60 sqm is often the secret to fast approval. Go over and you can trigger a full Development Application.
The silent budget killer
Find your sewer tie point before you pick a spot. Digging under a driveway or pumping uphill can triple your plumbing costs.
Not Sure What Your Build Will Really Cost?
Use our free on-page calculator to estimate preliminaries, site costs, the build and finishes before you read another guide or call a supplier.
Open the cost calculatorLatest Guides
Secondary Dwelling Rules Differ Across Australian States (2026)
Disclaimer: This article is for general information only and is not planning or legal advice. Always confirm current rules with…
Read the guideGranny Flat Parking Requirements: Australian State Guide
NSW complying development for secondary dwellings up to 60 m² usually needs no extra parking space. Victoria depends on zone…
Read the guideDual Occupancy vs Granny Flat: Planning Differences Explained
A dual occupancy puts two similar dwellings on one lot and is often planned with later subdivision in mind. A…
Read the guideTasmania Clarifies No Extra Parking for Secondary Residences
Tasmania’s Draft Planning Scheme Amendment 01-2026 includes a practical clarification for property owners: no additional car parking space is required…
Read the guideHIA Welcomes Tasmania’s 90sqm Granny Flat Proposal
The Housing Industry Association (HIA) has lodged a submission supporting Tasmania’s Draft Planning Scheme Amendment 01-2026, which proposes lifting the…
Read the guideGranny Flat Approval Process Australia: CDC vs DA Decision Tree (2026)
Granny flat approval process australia is a planning pathway plus a building pathway. In NSW the common fork is CDC…
Read the guide
