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CodexValley

Preliminary Cost Worksheet

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Get an early project cost from floor area, your own rates per area and lump sums, with fees and contingency.

Your list

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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.