Calculate the area and volume of your works to see if planning permission is required

It is vital to know the volume of a proposed development if you are planning a new building or extending an existing one.

Most buildings and extensions have sloping roofs - making the calculation of volume a tricky task. It is important to get it right if you are deciding whether planning permission will be needed.

This tool lets you calculate the volume of a number of different kinds of building or extension.

(opens in a new window which you may need to resize)

Requires Flash. Download the free plug-in from Adobe.