This is in no way binding and is dependent on Local Authorities, but may be used as a guide
Applications for approval normally involve a fee, normally related in some way to the value of the development.
Where the development is more than just a simple extension, it is worth considering employing an architect to draw up the plans, submit them to the Local Authority, obtain the approval and then to oversee the work. A professional architect will have professional insurance in case anything should go wrong and should know the Local Officials and their particular foibles.
Every application for Planning Permission or Building Regulations is, to an extent, unique. While the following are general rules, it is impossible to define all the regulations applying to a specific development - Local Authorities have some thick books of rules rather than just these few pages. It is always good advice to consult your local planning/building control officers early to avoid any costly abortive work. If work is carried out without the necessary approvals, the local authority can issue an enforcement notice requiring (at best) retrospective approval or (at worst) demolition of the work completed.
Although the functions of Planning Officials and Building Inspector are separate, the two will often be found in the same building; they are normally very helpful and offer authoritative guidance.
Normally Planning Permission or Building Regulation approval is not required provided that:
If at all in doubt contact your local authority for clarification. No charge will be made if no planning permission is required.