Garden room cost calculator: Herts & Bucks

It depends mainly on size, what the room is for and the extras you add. The calculator on this page gives a rough range from your choices. Guide figures for fitted rooms, including VAT. Not a quote: your written quotes depend on your plot. Only a builder who visits your garden can give a real price.

It is a guide for planning, not a quote. It cannot see your garden, ground, access or the finish you want. Use it to compare options, then get written quotes for the exact price.

A bigger floor area, plumbing and drainage (a shower room, WC or kitchenette), a reinforced floor, sound insulation, air-con, extra glazing, a long power or water run from the house, and hard access that means materials are carried through the house.

No. An office is the simplest build. Gyms usually need a stronger floor and ventilation. Studios put more into light and sound. An annexe, where someone sleeps, needs building regulations sign-off and is usually the biggest step up.

In England most garden rooms count as permitted development, within limits on height, size and position. The rules are tighter in conservation areas, on listed properties and in the Chilterns National Landscape. Your builder checks the rules for your plot before you commit.

Use the form under the calculator. We match you with up to 3 local builders who each give a written quote after a free visit. It costs you nothing.