An outbuilding can be used in different ways:

  • Gym
  • Home Office
  • Study Room
  • Swimming Pool
  • Sauna
  • Games Room

It all depends on the intended use of the building, whether it’s used all year round, or during the warm seasons. The use of the outbuilding will determine which materials will be required to make it suitable.

Types of Outbuilding

Modular – A modular outbuilding is flat packed and ready to be fitted. It can be ordered and pre-built to be assembled on site.

Bespoke – A bespoke option is where the outbuilding is designed and built according to your needs with a planner, architectural designer and builder.

Planning Permission

An outbuilding can be erected under permitted development rights without the need to apply for planning permission to the local council under Class E, Part 1, Schedule 2 of The Town and Country Planning (General Permitted Development) (England) Order 2015.

This all depends on the planning history of the property and the local council. A planning expert can confirm whether there are any constraints restricting the erection of an outbuilding. 

If there are no constraints, then it can be built without planning permission, subject to conditions and limitations. A planning expert can assess the proposed outbuilding in terms of its use and dimensions and make sure it complies with permitted development.

Bigger outbuildings and different types of uses may require planning permission. This is where a planning expert’s knowledge and experience will help you to maximise the potential of your desired outbuilding whilst complying with the local plans and policies of the area. 

Bigger outbuildings and different types of uses may require planning permission.

Building Control

Smaller outbuildings that are less than 15 square metres and propose no sleeping accommodation, then usually it doesn’t require to comply with Building Regulations.

For outbuildings bigger than 15 square metres or/and propose sleeping accommodation, then it usually requires compliance with Building Regulations. An architectural designer will draw up detailed plans of the outbuilding providing specifications for the building inspectors to complete their assessment and approve the build.


The cost of the outbuilding depends on a number of factors; the use, size, materials, insulation and finishes. 

A simple shed can cost around £750, whereas a bespoke games room, which will require heating, insulation, ventilation and electricity, would be more costly.