What kitchens, bathrooms, extensions, second storeys and granny flats tend to cost, why, and the state rules that shape every job.
This section explains what moves the price of a renovation in Australia and the rules that apply before any work starts. Every cost figure here is an illustrative range built from stated assumptions (size, finish level, structural work, location and professional fees), not a quote or market survey. Use the ranges to sanity-check a builder's price, not to replace one.
Start with the pillar guide to renovation costs, which shows how the cost drivers stack up. Then read the guide for your project type: kitchen, bathroom, ground-floor extension, second storey, granny flat or knock-down rebuild versus renovating.
Before signing anything, check the state-by-state thresholds for builder licences, written contracts, deposits, cooling-off periods and home warranty insurance. These figures differ between NSW, Victoria, Queensland and the other states and territories, and Victoria is part-way through contract reforms in 2026, so every guide points you to the official source to confirm the current position.
Costs, Price Drivers and 2026 Rules
What drives bathroom renovation costs in Australia, illustrative ranges for budget and mid-range finishes, waterproofing rules, strata approvals and quote traps.
Costs, Price Drivers and 2026 Rules
Illustrative granny flat costs in Australia, what drives them, state approval pathways for secondary dwellings, services connections and the contract rules to check.
Costs, Price Drivers and 2026 Rules
How to estimate a ground-floor home extension in Australia, from footings and roof tie-ins to approvals, with illustrative per-m² bands and a worked example.
Costs, Price Drivers and 2026 Rules
How Australian renovation costs are built up, the drivers that move them, illustrative ranges by project type and the 2026 rules to check before you sign.
Costs, Price Drivers and 2026 Rules
What drives kitchen renovation costs in Australia, illustrative ranges by finish level, layout changes, appliance packages and how to read a kitchen quote.
Costs, Price Drivers and 2026 Rules
How to decide between a knock-down rebuild and a major renovation in Australia, comparing costs, approvals, time, tax and risk, with an illustrative worked comparison.
Costs, Price Drivers and 2026 Rules
State-by-state thresholds for builder licences, written contracts, deposit caps, cooling-off periods and home warranty insurance for Australian renovations, as of October 2026.
Costs, Price Drivers and 2026 Rules
What makes a second-storey addition expensive in Australia, illustrative per-m² ranges, the structural checks, approvals and hidden costs of going up.
