Planning permissions for loft conversions

So you’ve decided to go ahead with a loft conversion?

Modern Attics wants to take you through the process of planning permissions. Planning permissions used to be applicable to all loft conversions and ground floor extensions to check the suitability of carrying out the work. Since 2008 however, changes in the planning laws made it possible for some conversions to go ahead without planning permissions if they are within the permitted development allowance. This relaxation of the original rule has helped to limit the encountered difficulties of the past where some loft conversions were restricted by strict regulations and not allowed to be built to their fullest potential.

Of course there are still a number of exceptions to the permitted development allowance. All flats and maisonettes, purpose built or otherwise, always require planning permission for loft conversions. Other exceptions include:

  • Properties listed or located in conservation areas
  • If the height of the roof is being increased
  • If a terraced house is extending its roof (addition of dormer, hip to gable) by more than 40 cubic metres
  • If a semi-detached or detached property (with addition of dormer, hip to gable) extends its roof more than 50 cubic metres

Proposals must be tailored to meet the local Council’s policy design guidelines. They can restrict or limit the available options depending on your plans. The Council is always involved to some extent, even for loft conversions that can be built within permitted allowance. They still need to issue a lawful development certificate in order for the work to be carried out.

Beyond the immediacy of obtaining planning permissions from the Council before work can begin, the other considerations are on the part of the builders. As professionals in this area Modern Attics can list for you the factors that we must assess before commencing any loft conversion.


Access is a very crucial consideration for a loft conversion. Ladders are not appropriate – stairs are required, which means you need to consider the type of stairs that you would like installed. The necessity here is chiefly because of safety concerns. Stairs provide a safe escape route in case of emergencies or a fire.  The staircase must discharge near to a door that leads to an external exit.

UK Building regulations require loft floors, walls and doors to be fire resistant up to a specified period (approximately 30 mins). The doors and windows will be assessed under these regulations.


This one is obvious. If a loft conversion is being tailored to create a new room (bedroom, office etc) then a new floor has to be installed as most attics are not designed to support heavy loads. Assessments need to be carried out on the roof structure, particularly skylights, dormers and load bearing walls including their foundations. The process of converting a loft must be carefully carried out so that the overall stability of the roof is not adversely affected. Structural elements such as beams, posts and trimmers must also be assessed.


There is a general guide on ventilation from standard Building Regulations on how to create a healthy living space with clean air. Another purpose of ventilation is to prevent condensation.


Going green is a good thing. The materials used in construction for the walls and roof are designed to keep out the elements but retain heat, effectively reducing heat loss. This is one of the best ways to conserve energy and cut down on fuel bills.

As with any loft conversion process the building controls ensure that alterations are carried out correctly so problems are not caused at a later stage. Changes to a home should always be noted in house plans anyway.

Modern Attics has had long experiencing tackling loft conversions and dealing with planning permissions so if you need more information or advice

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