The following are planning permission guidelines, It's the householders responsibility (not the installer) to apply for planning permission, if you are unsure, check with your local council.
Decking Planning permission and building regulations
Decking in a back garden, does not normally need planning permission.
Height:, planning permission will not be required if;
Planning departments control the use of land and what's built on it. It's enforced by local planning authorities (LPAs).
Under certain circumstances householders may need to apply for planning permission when considering building an extension, converting a loft space even paving a front garden. If you build without first gaining permission you can be legally forced to have the building restored to its original.
For a new building you can submit an outline planning application to check whether it's acceptable in principle. Permission lasts for three years.
Full planning permission lasts for three years and work should normally start within three years or you may need to reapply.