Understanding Planning Permission for Loft Conversions

Loft conversions can be an excellent and cost-effective way of adding space and value to your home. But you may be wondering if you need planning permission for a loft conversion. Read below to find out more.

4/6/20244 min read

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Do I Need Planning Permission for a Loft Conversion?

If you are considering a loft conversion for your home, one of the first questions that may come to mind is whether or not you need planning permission. The answer to this question depends on several factors, including the type of conversion you are planning and the specific regulations in your area.

Permitted Development Rights

In many cases, loft conversions can be carried out under what is known as permitted development rights. These rights allow homeowners to make certain changes to their properties without the need for planning permission. If you are simply looking to convert the loft space into extra space, without making changes to the roof, then in the vast majority of cases you will not need planning permission.

If you are adding rooflights, dormer windows or altering the roofspace, then your works may well come under permitted development rights. However, there are certain limitations and conditions that must be met in order to qualify for permitted development.

Permitted development rights for loft conversions require the following conditions to be met:

  • any part of the dwellinghouse cannot exceed the highest part of the existing roof;

  • the works cannot project forwards from a roof slope of the principal elevation of the house (the front of the house) and fronts a highway;

  • the cubic content of the new roof space cannot exceed 40 cubic metres in the case of a terrace house or 50 cubic metres for semi-detached or detached houses;

  • the house cannot be located in a protected area - known as Article 2(3) land, which includes World Heritage Sites and Conservation Areas, nor can the house have used Class AA permitted development rights to add an additional storey.

  • other associated works such as verandah's, balcony's and alterations to chimneys or soil pipes are covered by other permitted development rights.

Permitted development rights for loft conversions typically include:

  • The conversion must not exceed a certain volume or extend beyond the existing roof slope.

  • The materials used must be similar in appearance to the existing property.

  • The conversion must not include any balconies, verandas, or raised platforms.

  • No part of the conversion can be higher than the highest part of the existing roof.

  • The conversion must not result in any significant changes to the external appearance of the property.

In addition to the above, permitted development rights apply conditions to the materials to be used. Importantly:

  • materials for the external work must be of a similar appearance to the existing house;

  • other than in the case of hip-to-gable extensions, the eaves of the roof are maintained or reinstated; and the edge of the enlargement cannot be less than 0.2 metres from the eaves;

  • other than in the case of an enlargement which joins the original roof to a rear or side extension, no part of the enlargement extends beyond the face of any external wall of the original dwellinghouse;

  • any window inserted on a wall or roof slope forming a side elevation must be obscure glazed and any openings must be 1.7 metres above the floor.

Beware of Restrictions

Permitted Development Rights can be removed from homes, either through what is known as an Article 4 Direction, or a planning condition. This information can usually be gathered from your local Council website. Council's often remove Permitted Development Rights in sensitive areas, such as Conservation Areas, and some new-build housing estates have had permitted development rights removed.

If permitted development rights have been removed, you will need planning permission to carry out these works.

If you live in a flat, it is important to remember that permitted development rights only apply to houses. Similarly, if your home was converted from a commercial use using a change of use permitted development right, such as Class MA, permitted development rights do not apply to your home. Therefore, if you want to make changes to your flat, you will need planning permission.

What is a Lawful Development Certificate?

If you wish to proceed with a loft conversion, we recommend seeking a Lawful Development Certificate or Certificate of Lawfulness from your local Council.

This confirms that your works are in line with permitted development rights.

This can give you peace of mind, and also acts as valuable confirmation for any perspective purchasers of your property when you come to sell your home.

Cedar Planning are experienced in gaining successful Lawful Development Certificates for our clients.

Building Regulations

In addition to planning permission, you will also need to comply with building regulations when carrying out a loft conversion. Building regulations are a set of standards that ensure the safety, accessibility, and energy efficiency of a building.

Building regulations for loft conversions cover various aspects, including:

  • Structural stability

  • Fire safety

  • Insulation

  • Ventilation

  • Staircase design

  • Sound insulation

It is essential to obtain building regulations approval for your loft conversion to ensure that the work meets the required standards. This approval can be obtained from either the local authority or an approved private building control inspector.


Before embarking on a loft conversion project, it is crucial to determine whether or not you need planning permission. In many cases, loft conversions can be carried out under permitted development rights. However it is recommended that you seek a Certificate of Lawfulness or Lawful Development Certificate from your local council.

If your loft conversion does require planning permission, you will need to submit a planning application to your local authority. Some councils take a negative view of loft conversions, so if your works comply with permitted development rights, the lawful development certificate route is always preferred to a planning application.

In fact, Cedar Planning have dealt with cases where planning permission was refused for a proposal which was then found to comply with permitted development rights as confirmed by a Lawful Development Certificate granted by the Council. Contact us today for a free no-obligation quote.

By understanding the planning permission requirements and building regulations for loft conversions, you can proceed with your project confidently and ensure that it is carried out legally and to the highest standards.