Home calculators
Property and home-project budget tools — renovations, extensions, energy costs and moving budgets.
Renovation budget estimator
A rough renovation budget from the area being worked on and a cost-per-square-metre rate.
Extension rough-cost estimator
A very rough single-storey extension budget from the floor area and a cost rate.
Loft conversion budget estimator
A rough loft conversion budget by conversion type — rooflight, dormer or hip-to-gable.
Painting budget estimator
Full supply-and-fit budget for painting a room — materials and a decorator's labour.
Flooring budget estimator
Full supply-and-fit budget for new flooring — materials and labour.
Solar payback estimator
Roughly how many years a home solar PV system takes to pay for itself.
Moving-cost planner
Build a moving-cost scenario from a local quote or your own base estimate, distance charges and a packing allowance.
Home maintenance budget planner
Build an annual home-maintenance budget scenario from property value and a percentage you choose.
Using budget estimators sensibly
The project estimators here multiply a floor area or room count by a per-unit rate, then add a contingency. They are designed to give a first sense of scale — whether a project is likely to cost thousands or tens of thousands — before you ask for quotes. They are not quotes themselves.
Replace the default rates
Any prefilled rate is an adjustable example, not a live market quote or a price supplied by a builder. Replace it with your own current local quote or estimate; regional labour costs, access, specification and project scope can change the result substantially.
Keep a contingency
Older properties in particular hide surprises once work starts. The contingency percentage is shown separately so you can see exactly how much of the total it represents and adjust it.
Remember the costs outside the build
Unless you include them in your own rate, allow separately for VAT, planning/building-control fees, design and structural engineering, surveys, utility work, finishes and temporary accommodation. What is included in a builder's quote varies, so check its scope rather than assuming the per-square-metre figure covers the whole project. The extension and loft conversion estimators link to official planning guidance on what permissions may apply.