Total project cost
This includes your entered renovation cost plus the contingency percentage you selected. A higher contingency makes the scenario more cautious.
UK renovation planning calculator
Renovation ROI Calculator
Estimate a planning-level renovation ROI scenario by comparing your project cost with estimated potential property value uplift, contingency and selected transaction allowances.
This calculator helps you test whether a renovation spend feels proportionate before requesting quotes or making a larger property decision. It does not predict sale price, guarantee a return or replace advice from a qualified professional.
Results are planning estimates only. This is not financial advice, mortgage advice, valuation advice, estate agency advice, tax advice, legal advice or investment advice.
Calculator
Estimate renovation ROI
Enter your own planning figures. If you do not yet have a project cost, use a relevant CostIntel room calculator first, then bring that estimate back into this tool.
Result guide
What the Renovation ROI Calculator shows
The calculator compares the cost side of your project with an estimated potential uplift scenario. A positive result means the selected uplift assumption is higher than the selected project cost and allowances in this scenario.
Estimated potential uplift
This is based on your current estimated property value and the selected uplift assumption. It is not a valuation or sale price prediction.
Illustrative ROI
This compares the net estimated uplift with the total project cost. Negative results show where costs are higher than the selected uplift scenario.
Methodology
How renovation ROI is calculated
Renovation ROI is not a guarantee of added value. CostIntel treats it as a planning comparison between what you may spend and the value uplift scenario you are testing.
The uplift percentage is shaped by the project type, project quality, selected uplift assumption, market sensitivity and any custom percentage entered by the user.
You can review CostIntel’s wider calculation approach on the methodology page, the pricing data page and the guide to how costs are calculated.
Original CostIntel insight
Value Confidence Flag
The Value Confidence Flag helps separate a promising-looking number from a scenario that may be too sensitive to assumptions.
What the flag checks
The flag looks at the uplift assumption, project quality, contingency, time horizon, market sensitivity and project type. A higher ROI result may still need caution if it depends on optimistic assumptions or a low contingency allowance.
Why it matters
Renovation ROI can look stronger when costs are understated or uplift is overstated. The confidence flag reminds users to check the assumptions behind the number, not just the percentage result.
Scope
What the estimate includes and excludes
This calculator is for early planning. It helps structure assumptions, but it cannot replace property-specific professional checks.
| Included in the calculator | Not included in the calculator |
|---|---|
| User-entered renovation cost | Contractor quote accuracy |
| Contingency allowance | Full professional property valuation |
| Estimated potential uplift percentage | Mortgage affordability or lending checks |
| Simple transaction allowance | Legal, tax or investment advice |
| Market sensitivity setting | Survey findings or hidden defects |
| Project type and quality assumption | Guaranteed sale price or buyer demand |
Practical scenarios
Example renovation ROI scenarios
These examples show how the calculator can be used. They are not recommendations about which renovation provides the best return.
Kitchen renovation before resale
A homeowner may use a kitchen cost estimate, select a standard or mid-range finish, then compare conservative and typical uplift assumptions before deciding whether to request quotes.
Whole-home refresh
A user planning flooring, painting and minor improvements may compare a lower-cost refresh against a modest uplift assumption and a realistic contingency allowance.
Extension or major works
A larger project may need a higher contingency and more professional input. The ROI result should be treated as market-sensitive, especially for short resale timelines.
Professional checks
When this ROI estimate is not enough
Use this calculator to prepare, not to replace advice. Get qualified help if you are relying on the result for a sale, purchase, remortgage, borrowing decision or high-value renovation.
Professional input is also important for structural work, extensions, layout changes, damp, subsidence, roof problems, older electrics, planning permission, building regulations or leasehold issues.
Input quality
How to improve the quality of your scenario
Use recent contractor quotes where possible, allow a realistic contingency and avoid relying only on optimistic uplift assumptions. For resale decisions, compare the result with local market evidence and professional valuation advice.
If you are still estimating the project cost, start with the Renovation Budget Planner or a relevant Interior Cost calculator before returning to this page.
Related tools
Related project planning and renovation cost tools
Use these calculators together to move from project pricing to wider renovation planning.
Project Planning Tools
Return to the hub for all renovation planning calculators.
View Project Planning ToolsProperty Value Uplift Calculator
Estimate possible uplift from project type, property type and market setting.
Estimate property value upliftRenovation Budget Planner
Build a structured budget before testing ROI assumptions.
Plan a renovation budgetBuild vs Buy Calculator
Compare improving your current home with buying elsewhere.
Compare build vs buyKitchen renovation costs
Estimate kitchen project cost before testing an ROI scenario.
Use the kitchen cost calculatorBathroom renovation costs
Build a bathroom cost estimate for budget and uplift comparisons.
Use the bathroom cost calculatorFlooring costs
Estimate flooring costs for a refresh or wider renovation plan.
Use the flooring cost calculatorPainting costs
Estimate decorating costs before setting final planning assumptions.
Use the painting cost calculatorFAQs
Renovation ROI Calculator FAQs
What is renovation ROI?
Renovation ROI compares the estimated net uplift from a renovation with the estimated cost of completing it. On CostIntel, this is shown as a planning scenario, not a guaranteed return.
How is renovation ROI calculated?
The calculator estimates potential value uplift, subtracts project cost, contingency and selected transaction allowance, then compares the net result with the total project cost.
Is renovation ROI guaranteed?
No. Actual outcomes depend on property type, location, buyer demand, quality of work, timing, local market conditions and professional valuation.
Which renovations usually affect value?
Kitchens, bathrooms, whole-home presentation, added usable space, energy efficiency improvements and consistent finishes may affect buyer appeal, but the result depends on the property and local market.
Should I use this calculator before getting quotes?
Yes. The calculator can help you test whether a planned spend feels proportionate before requesting quotes. Contractor quotes are still needed for real project pricing.
Is this financial or valuation advice?
No. The calculator provides planning estimates only. It is not financial advice, investment advice, mortgage advice, estate agency advice or a property valuation.
Why can a high ROI result still be risky?
A high result may depend on optimistic uplift, low contingency, strong buyer demand or a project cost that later increases. The Value Confidence Flag helps show when the result is sensitive to assumptions.