Preliminary Cost Worksheet
AvailableGet an early project cost from floor area, your own rates per area and lump sums, with fees and contingency.
Your list
Edit, add or remove entries. Everything is worked out in your browser and nothing is sent to our server.
The list is kept only in this browser so it is here when you come back. Turn this off on a shared or public computer, and use Export CSV to keep a copy.
Summary
About this tool
Get an early idea of what a building project may cost before you have detailed drawings. Price each cost element as a rate per unit of floor area or as a lump sum, then add design fees, contingency and tax. You get a total and a cost per unit of floor area, and your figures stay in this browser.
How it works
- An element priced per area is its rate times the floor area. A lump sum is used as it is.
- Professional fees are a percentage of the building and site cost.
- Contingency is a percentage of the building cost plus fees, and tax is a percentage of all of that together.
- Cost per unit of floor area is the final total divided by the floor area.
This is a preliminary estimate for planning and shopping lists. It is not a structural design, a safety check or a building-code approval. Ask a qualified professional before you build.
Common questions
Should I use square metres or square feet?
Either, as long as the floor area and every rate per area use the same unit. The cost per unit of floor area is then in that unit too.
How accurate is an early cost estimate?
Only as good as the rates you enter, and early estimates often change as the design develops. Keep a contingency and update the worksheet when real quotes arrive.
What contingency percentage should I choose?
The worksheet starts at 10%, but that is only a starting value. Ask your designer, builder or quantity surveyor what suits the size and risk of your project.
Your entries stay in your browser. They are not uploaded, and you can delete them at any time with Clear all.
Related tools
Room Area Calculator
AvailableGet the floor, ceiling and wall area of a room, with doors and windows taken off.
Construction
Paint Calculator
AvailableEstimate how many litres and tins of paint a job needs, with coats and waste.
Construction
Floor Tile Calculator
AvailableCount the tiles and boxes a floor needs, with an allowance for cuts and breakage.
Construction
Concrete Volume Calculator
AvailableWork out how much concrete a flat slab needs in cubic metres and cubic yards.
Construction