Garden room estimator

What this works out

The steps

Work through these calculators in order. Each one takes the measurements from the step before.

  1. Base (as the shed base estimator)
  2. Stud walls
  3. U-values
  4. Insulation thickness
  5. Flat roof
  6. Electrics: maximum demand
  7. Electrics: armoured cable size

Costs come only from your own prices: there are no price figures on this site.

Questions for your builder and electrician

  • Does the garden room need planning permission (height, distance to the boundary, use) or building control (size, sleeping in it)?
  • How will the armoured cable get from the house, and how deep will it be buried?
  • Is the supply big enough for heating in the garden room as well as the house?
  • What base does this size of building need on this ground?

Before you start