Before deciding on the most suitable type of loft conversion for your home, one of the important factors you will want to consider is whether or not you need planning permission. Whether it is a dormer, rooflight, or hip to gable roof loft conversion, there are multiple different aspects of the project that will need to be considered before deciding whether you will need to submit a planning application to the local council. Factors such as the size of the project and the location of your property will affect whether or not you will need planning permission, so it is worth clarifying these important details. Allow us to explain everything you need to consider.

Will you need to apply for loft conversion planning permission?

Converting the loft of a house is classed as permitted development, subject to specified conditions. If these conditions are not met or permitted development rights are not applicable in the area where your property is based, then an application for planning permission will need to be submitted.

To avoid submitting a planning application, your house must not:

  • Be a building with one or more flats, or a flat within a building such as this.
  • Have already had additional storeys added under permitted development rights.
  • Be on designated land – conservation areas, areas of outstanding natural beauty, National Parks, or World Heritage Sites.

How can you avoid planning permission for your loft conversion?

To avoid going through the planning permission process, you should follow these rules to make sure your loft conversion will meet permitted development rules:

  • Materials used must be similar to the existing house.
  • Construction must not exceed the height of the existing roof.
  • The total area of this new space cannot exceed 40 cubic metres for terraced houses and 50 cubic metres for semi-detached houses. It is important to be aware that any previous roof extensions that have been carried out will count towards this allowance.
  • The extension cannot go beyond the existing roof slope at the front of the house.
  • Must not include balconies, verandas, or adjustments to the chimney.
  • Side-facing windows should be obscure glazed and must be 1.7 metres above the floor of the room if they are able to be opened.
  • Must maintain the original eaves of the roof and any enlargement should be set back, so far as practicable, at least 20cm from the original eaves.

What building regulations will you need to be aware of for your loft conversion?

Although planning permission may not be necessary, you will need building regulations approval when constructing your new loft conversion, which you will need to submit a full plans application for. This will be enforced by building control. These include:

Fire safety

Fire resistant doors and smoke alarms must be installed as part of your loft conversion, as well as stairs so that there is an escape route in the event of a fire.

Roof support

New floor beams and joists will need to be installed to support this new room, as well as any new walls to support the roof where existing supports may have been removed.

Sound insulation

The new loft space must be properly sound insulated so that noise cannot travel too easily between the loft and the rooms below.

To find out whether your loft conversion plans will require planning permission, we recommend you consult an architect or structural engineer. To turn your loft conversion plans into reality, consult our experts at Prime Construction. We are loft conversion specialists, who can manage the construction process of your new space, regardless of which option you decide is best. To speak to us regarding your project, give us a call on 01795 431378 or email

Contact our team at Prime Construction

If you would like to find out more about the network of architects that some of our clients have used, speak to our team today. Call us now on 01795 431378 or email to discuss your project with us.

Contact Us