Renovation ROI Calculator

A mid-range kitchen renovation typically costs between $25,000 and $45,000, covering new benchtops, cabinetry, appliances and a splashback. A mid-range bathroom sits between $15,000 and $35,000, with the national average around $26,000 according to HIA figures. These are starting points - labour accounts for 40-50% of kitchen costs, and bathrooms frequently uncover hidden waterproofing or plumbing issues once walls are opened. Your actual costs will depend on your state, the scope of work, and the tradespeople you engage.

The calculator automatically adds a 15% contingency buffer to your total renovation spend. This is the mid-range figure recommended by the Master Builders Association and ASIC MoneySmart for residential renovations - 10% is the minimum for purely cosmetic work, and 20% is more appropriate for structural changes. Kitchen and bathroom renovations in particular frequently run 20-30% over initial quotes, so building in a buffer before you start is one of the most practical steps you can take.

ROI (return on investment) measures how much value a renovation adds compared to what it costs. As an illustration, an ROI of 80% would mean a $10,000 spend adds roughly $8,000 to your property value. Based on 2025-26 Australian market data, painting a whole house ($6,000-$18,000) and landscaping ($5,000-$30,000) have historically been among the higher-return categories - in some cases the value added may exceed the spend - because they can lift street appeal and listing photos. Kitchens and bathrooms have also tended to deliver solid returns. Swimming pools sit among the lowest-ROI renovations at around 20-50% and can reduce buyer appeal because of maintenance costs and insurance impacts. These are general market patterns, not a guarantee: actual returns vary by suburb, timing and finish quality, and the final value added is determined by the market at sale.

Overcapitalisation is when you spend more on renovations than the local market will pay back in added property value. The calculator flags a warning when your planned renovation spend exceeds 10% of your current property value - the threshold identified by HIA and CoreLogic where additional spending typically stops adding proportional resale value. This is a guideline rather than a hard rule, and outcomes vary significantly by suburb and property type, so getting a local agent's view on comparable sales before committing to a large spend is worthwhile.

Under Help to Buy, improvements costing less than $21,000 within a 12-month period (the 2026-27 figure, indexed each 1 July) that do not need council approval can generally proceed without notifying Housing Australia, but they also leave the government's share unchanged. If the work totals $21,000 or more within 12 months, or needs council approval, you must notify Housing Australia before starting. For work of $21,000 or more, Housing Australia arranges valuations before and after, and the value added by the approved work is credited to you, which reduces the government's equity percentage. If you do not notify when required, you may not receive that equity credit and the government may retain its original share. The government's share can be up to 40% for new properties and up to 30% for existing ones. Housing Australia makes the final determination, so confirm the current rules with them before starting.

Under Help to Buy, you can buy back equity directly by paying Housing Australia in cash, with each payment generally needing to be at least 5% of the property's current market value. The tool compares that direct buyback cost against the renovation spend required to achieve a similar reduction in the government's equity percentage. Because renovation value-add is credited to you, a well-chosen renovation could reduce the government's share by an amount similar to a direct cash payment but at a lower out-of-pocket cost - though this is only an estimate based on the figures you enter and depends on the actual ROI of the renovations you select.

Structural work generally requires council approval - this includes removing load-bearing walls, extending the home, adding a bedroom through a conversion or extension, building a pool, or adding a carport. Cosmetic work like painting, replacing flooring, or a like-for-like kitchen or bathroom update typically does not require approval, though rules vary by state and council. Under Help to Buy, any renovation that requires council approval generally triggers the notification requirement regardless of cost, even if the spend is below the $21,000 improvement threshold. Always confirm approval requirements with your local council before starting work.