Renovation cost calculator
Build a first budget for a renovation from the floor area, a cost per area, the finish level, a contingency and tax.
Your estimate
Estimated total
£41,400
- Lower end
- £33,120
- Upper end
- £51,750
- Works before extras
- £30,000
- Contingency
- £4,500
- VAT / tax
- £6,900
Estimates for planning only — not a quote, survey or financial advice.
Sources for the pre-filled values — United Kingdom
- GOV.UK — VAT rates: standard rate 20% · Standard rate · accessed 2026-11-06 · Reduced or zero rates may apply to some energy-saving installations.
How this is calculated
Formula
- Works = floor area × cost per area × finish factor (basic 0.85, standard 1.0, premium 1.35)
- Contingency = works × contingency %
- Tax = (works + contingency) × tax rate
- Range = total × 0.8 to total × 1.25
Assumptions
- The cost per area is an example figure, not a current market price. Replace it with quotes from local contractors.
- Standard VAT rates are pre-filled (UK 20%, France 20%, Germany 19%, Spain 21%, Italy 22%); reduced rates can apply to some renovation and energy-saving work. In the US, sales tax depends on the state and is often included in contractor prices.
- Permits, design fees, structural work, hazardous-material removal and furniture are not included.