Building Regulations Information

What are building regulations?

If your loft conversion is intended for use as new accommodation, for example a bedroom, study or office then you will need to make a Building Regulations application. Building regulations are used to ensure that any building or alteration work meets the set standards for the design and construction of buildings, mainly to ensure the health and safety for those living in or around the building. They are also increasingly used to ensure that the building is energy efficient and that access to the building has been considered.

The following sections outline the main areas that must be considered. Houses with more than two storeys will need to meet similiar but more extensive requirements.


Generallly the exising timbers in your roof will not be strong enough to support the new floor. New timberwork will need to be installed and most often steelwork will be required as the span is normally too great for timber beams. Calculating the size of timbers or steelwork is certainly a job best left for the professionals. Any changes to the roof such as the addition of a dormer or velux windows will need to built correctly so that they do affect the roof structure

Fire Resistance, Means of Escape and Access

The floors, walls and doors in your house and loft conversion must be able to resist fire for the specified amount of time (this is normally 30 minutes). The aim of the requirements is that that there should be a fire protected path from the conversion to the outside. Under previous requirements a low level window and ledge were to be installed in the loft as a means of escape and self closers were required on the doors. It has now been deemed that escape via the loft is too dangerous and the main escape route should now be through the house.

The main stairways should be protected by installing fire rated doors on both storeys, self closers are no longer required for most houses. Fire doors may not be required for non inhabited rooms such as bathrooms and cupboards if they are deemed a low fire risk. When installing new fire rated doors dont forget that the hinges should also be fire rated. Interlinked, mains powered smoke alarms will be needed at each level and are an essential safety item, the Direct Gov website has a good guide to smoke alarms.

Most people opt for a traditional staircase to their loft conversion, other types of space saving staircases can sometimes be used if space is restricted. Be aware that space saving stairs can be very difficult for children and the elderly to use and should only be considered once all other options have been explored.

Energy Conservation

Ensuring that your loft conversion is properly insulated will keep the loft room cool in summer, warm in winter, reduce your reduce your CO2 output and will save you money by keeping your heating bills low. Most loft conversions now use modern high performance thermal insulation boards such as those manufactured by Celotex or Kingspan. To conserve energy your loft conversion should have as low a U-value as possible.


Proper ventilation is essential for both the living space and the roof space. Ventilation to the living space will prevent excessive condensation and build up of stale air. Ventilation to the roof space will prevent condensation that could cause problems such as rot and timber decay.

Further Reading

The best place to find out more about building regulations is via the governments planning portal website, they have a section on building regulations for loft conversions.