Building Control guidance - roof space conversions

Roof space or attic conversions require a Building Regulation application, i.e. a Full Plans application or Building Notice submission, where the intention is to provide:

  • An extra bedroom
  • A bathroom or en-suite
  • A playroom
  • A study/office
  • A fixed staircase

Where the intended use is to store lightweight items such as Christmas decorations, suitcases, general household items, etc. a Building Regulations application is not required - provided the access to the area is by ladder and not by a new staircase.

Ceiling joists are generally not intended to act as a floor and are not designed to support heavy loads.

Therefore it is important to inform the Building Control service and make a Building Regulations application where the proposed use is for anything other than light storage.

Why inform the Building Control service?

Building Control will help achieve the construction standards set out in the Building Regulations. Future sales of properties where work has been completed without Building Regulation approval can be difficult.

It is generally considered that roof conversions are the most complex of domestic building work. They should be designed and constructed by people aware of the health and safety aspects affecting building occupiers. The following points must be considered and catered for in roof space conversion:

  1. Floors, certain walls and doors are required to be structurally able to resist the effects of a fire for a specified period of time: usually 30 minutes in a typical domestic situation. Such provisions, among other things, are essential to ensure safe escape in the event of fire or other emergencies
  2. The new floor and room layout requires a safe and easy exit route in the event of fire. Careful consideration of this item is of critical importance
  3. The provision of an automatic smoke or heat detection system to give early warning of a fire is necessary
  4. A 30 minute fire resisting escape route needs to be provided to a final exit. Existing doors enclosing the escape route will need to be fire resistant (FD20) in most cases
  5. Sprinklers maybe help provide an alternative fire safety solution for open plan arrangements on the ground floor
  6. The structural adequacy of the 'new floor' has to be designed and checked to ensure it can safely support the new loads placed upon it, without suffering collapse or excessive deflection
  7. Thermal insulation will be required for the sloping ceilings, flat ceilings, stud walls, gable and party walls if present
  8. Ventilation is essential to most room areas to prevent unpleasant living conditions
  9. Condensation, if not properly catered for especially in areas where it cannot be seen, can cause problems. Certain roof space layouts and roof construction types require careful consideration of ventilation and vapour check barrier provisions
  10. The walls and roof of the roof space conversion require not only to keep out the rain and effects of damp but also reduce heat loss
  11. If a bathroom or shower room is to be included additional ventilation measures will be required to prevent excessive condensation

Electrical installations need to be either, installed by a Registered Part P Electrical installer, or inspected and tested by a Building Control surveyor (for which an additional charge is payable).

Other approvals

In addition to a Building Regulation approval you may also require planning permission in certain circumstances.