Planning Permission for Your Loft Conversion

You might be pleased to hear that most loft conversions are typically considered 'permitted development', meaning you won't need to apply for planning permission. However, this is only the case if your project adheres to a specific set of limits and conditions. If your proposed conversion doesn't meet these strict requirements, or if your property's permitted development rights have been withdrawn by your local council, then you will absolutely need to submit an application for 'Householder' or 'Full Planning Permission'.

When You'll Need Planning Permission for Your Loft

To qualify as permitted development and avoid needing a formal application, both your existing home and your planned loft conversion must fulfil the following criteria:

About Your Current Home:

• Your property must be a dwellinghouse (a single house), not a building containing multiple flats, nor a flat itself.

• Your house must not have previously gained additional storeys under permitted development rights.

• It should not have been converted into a home from a previous non-residential use under permitted development rules.

• It must not have been originally built as a 'New Dwellinghouse' through permitted development.

• Your property must not be situated on Article 2(3) designated land, which includes special areas like conservation areas or National Parks.

Restrictions on Your Proposed Loft Conversion:

• Any new materials you use should match the appearance of your existing house.

• The total volume added to your roof space (including any enlargements made previously) must not exceed the original roof space by more than:

  • 40 cubic metres if your home is a terraced house; or

  • 50 cubic metres for all other house types.

• The highest point of your finished loft conversion must not be taller than your home's existing roof.

• On the principal elevation of your house (the side that faces a highway), your conversion must not extend beyond the line of the existing roof slope.

• Your conversion cannot include any of the following:

  • Verandas, balconies (platforms that project outwards), or any raised platforms; or

  • The installation, alteration, or replacement of any chimney, flue, or soil and vent pipe.

• Any windows installed on the side of your property must use obscure glass (frosted). If these windows are designed to open, the opening part must be positioned at least 1.7 metres above the internal floor level of the room.

Important Exceptions to These Rules:

There are specific scenarios where some of the above restrictions do not apply:

• The rules regarding total volume and extending beyond the principal elevation (points 1 and 2 above) are not applicable to the relevant parts of any 'hip-to-gable' enlargement.

• None of the three points concerning total volume, maximum height, or principal elevation apply to the relevant sections of any enlargement that connects your original roof to the roof of an existing side or rear extension.

Key Definitions

What is a Balcony?

The government's official technical guidance clarifies that a 'balcony' is typically a platform, complete with a rail, balustrade, or parapet, that extends out from an upper level of a building. However, a 'Juliet' balcony – which lacks an external platform and therefore offers no outdoor access – generally falls within permitted development rules.

Understanding Article 2(3) Designated Land

This term refers to land found within specific protected or specially designated areas, including:

• A conservation area; or

• An Area of Outstanding Natural Beauty; or

• An area specifically identified by the Secretary of State to enhance and protect the natural beauty and amenity of the countryside; or

• The Broads; or

• A National Park; or

• A World Heritage Site.

Where to Find More Information

To fully understand how these permitted development rules apply to your unique loft conversion project, we strongly recommend you consult the government's comprehensive technical guidance. These official documents will provide the detailed information you need:

1. The Town and Country Planning (General Permitted Development) (England) Order 2015, Schedule 2, Part 1, Class B

2. Permitted Development Rights for Householders – Technical Guidance