🧮 Free Cost Tool

Granny Flat Cost Estimator

Select your state, build type, size and fixture level to get a free estimated cost range in AUD — with a full breakdown by category. No sign-up needed.

✅ Free ✅ No Sign-Up ✅ AUD & Metric ✅ NSW · WA · VIC · QLD

Enter Your Details

Fill in all four fields below, then click Calculate.

Your Estimated Cost Range
$0 – $0 AUD
Cost CategoryEstimated Range
Total Estimated Range
⚠ Estimates only. These figures are indicative ranges based on typical Australian market rates as of 2026. Actual costs vary significantly by builder, site conditions, council, and material prices. Always get at least three professional quotes before committing to a build.
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How Granny Flat Cost Estimator Works

Three steps — under two minutes.

1
🏠
Enter Your Details

Select your state, build type, granny flat size, and preferred fixtures level from the dropdowns above.

2
🧮
We Apply Real AU Data

The tool applies current Australian per-sqm build rates for your state and adjusts for your chosen fixture level and build type.

3
📋
Review Your Breakdown

You get a total AUD cost range plus a breakdown by category — build, site prep, council, utilities, and design. Then get real quotes from local builders.

Want the Full Picture?

Read the detailed cost guides for your state — including hidden costs, council fees, and what drives prices up or down.

🇦🇺 National Granny Flat Cost Guide 2026 📍 NSW Granny Flat Cost Guide 2026 📍 WA Granny Flat Cost Guide 2026 📍 VIC Granny Flat Cost Guide 2026 ⚠️ Hidden Costs of Building a Granny Flat 📐 Granny Flat Cost Per Square Metre

Ready to Get Real Quotes?

Use your estimate as a starting point — then get free, no-obligation quotes from local granny flat builders in your state.

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Frequently Asked Questions

Common questions about granny flat build costs in Australia.

Granny flat costs in Australia typically range from $80,000 to $250,000+ depending on state, size, build type and finish level. A basic 30sqm kit home in WA starts around $42,000, while a premium 70sqm custom-built granny flat in NSW can exceed $220,000. Use the estimator above to get a range specific to your situation. Read our full national cost guide for a detailed breakdown.
Kit homes are the most affordable option — typically 20–30% cheaper than a custom-built granny flat of the same size. Modular granny flats sit in the middle. Choosing basic fixtures and a smaller size (30–45sqm) also significantly reduces total cost. Keep in mind that site preparation, council fees and utilities connection are additional costs that apply regardless of build type. See our hidden costs guide for what else to budget for.
The estimates are indicative ranges based on typical 2026 Australian market rates by state, build type and fixture level. They are a useful starting point for budgeting and comparing options — but actual costs vary significantly by builder, site conditions, council area and material prices at the time of build. Always get at least three professional quotes before committing to a project.
The estimator covers the five main cost categories — build and construction, site preparation, council and approval, utilities connection, and design and plans. It does not include landscaping, fencing, driveway works, furniture, white goods, or ongoing costs such as insurance and maintenance. Read our hidden costs guide for a complete list of additional expenses to budget for.
Council and approval fees typically add $3,000 to $15,000+ to the total build cost, depending on the approval pathway and state. A NSW CDC is typically $3,000–$6,000 via a private certifier. A DA through council in any state can cost $5,000–$15,000+ including application fees, reports and certification. WA requires only a Building Permit — typically $1,500–$3,000. Always confirm council fees with your certifier or builder during the quoting stage.
Generally yes — a well-built granny flat can increase property value by more than its build cost in high-demand rental markets, particularly in Sydney, Melbourne and Perth. The uplift depends on location, build quality, and local demand. Use our ROI Calculator to model the full return including rental income and property value uplift over your chosen time period.