Do you need planning permission? Start with permitted development

Many home extensions and loft conversions can be carried out under permitted development rights, which means you do not need to submit a householder planning application. For a single-storey rear extension, the standard limits are 3 metres beyond the rear wall for a terraced house, 4 metres for a semi-detached or detached house. Under the neighbour consultation scheme, larger single-storey rear extensions may be possible: up to 6 metres for terraced and semi-detached homes, and up to 8 metres for detached homes. The extension must not be higher than 4 metres, and eaves must not exceed the existing eaves. Side extensions are usually limited to a single storey, no more than half the width of the original house, and must not be forward of the principal elevation or closer to the highway. Loft conversions have volume limits: 40 cubic metres for terraced houses, 50 cubic metres for semi-detached and detached houses. Roof extensions must not extend beyond the plane of the existing roof slope on the principal elevation, and materials should match. Balconies, verandas and raised platforms are not permitted development.

When a householder application is the right route

If your plans exceed the permitted development limits, or if your home is a flat, maisonette or listed building, you will need to apply for householder planning permission. Two-storey extensions, side extensions that are wider than the PD allowance, front extensions, and dormers that face the principal elevation will normally require an application. Properties in conservation areas, areas of outstanding natural beauty, national parks and World Heritage Sites often have tighter rules. In a conservation area, for example, side extensions, roof extensions and cladding usually need permission, even if they would otherwise be permitted development. An Article 4 direction can remove permitted development rights entirely, so always check your council's local constraints and the property's planning history before you assume you can build.

How neighbours are consulted

For a householder application, the local planning authority will usually notify adjoining neighbours in writing and give them 21 days to comment. The council may also display a site notice and, in some cases, advertise in the local press. Neighbours' comments are considered on planning grounds: overlooking and loss of privacy, overshadowing and loss of light, the scale and design of the proposal, traffic and parking, and drainage. Concerns about property values or loss of a private view are not normally planning matters. If you are using the neighbour consultation scheme for a larger rear extension, the council will consult adjoining owners directly. If they object, the council will decide whether the impact on them is acceptable. Talking to your neighbours early, with drawings in hand, can prevent misunderstandings and reduce the risk of objections.

Drawings and documents for a householder application

A complete householder application normally needs a location plan at 1:1250 or 1:2500, showing the site in relation to surrounding streets and buildings. You will also need a site plan or block plan at 1:500 or 1:200, with the application site edged in red and any other land you own edged in blue. Existing and proposed floor plans and elevations are essential, usually at 1:100 or 1:50. For loft conversions, include a roof plan and a section showing the proposed headroom and dormer or rooflight positions. Drawings should show dimensions, materials, window and door positions, boundary treatments, and finished floor levels. A short design and access statement is not always required for householder applications, but it can help in sensitive areas or where the design needs explanation. If your property is listed or in a conservation area, you may also need a heritage statement. In flood zones, a flood risk assessment may be requested. Check your council's local validation checklist before submitting, as requirements vary.

Practical steps for a smoother approval

Before you apply, ask your local planning authority for pre-application advice. This is not free everywhere, but it can save time and money by confirming the principle of development and highlighting design issues. Use a designer who knows your local area and the council's policies. Keep the design modest, use materials that match the existing house, and avoid overbearing impacts on neighbours. Remember that planning permission and building regulations are separate: approval under one does not imply the other. If you are building near a boundary, the Party Wall etc. Act 1996 may apply, and you must serve notices on affected neighbours. Also check whether you need permission for a dropped kerb, a new driveway, or changes to trees covered by a Tree Preservation Order.

Timing, fees and next steps

Householder applications in England currently attract a fee of £258, with different scales in Wales, Scotland and Northern Ireland. The council normally determines a householder application within 8 weeks, although complex cases can take longer. Once permission is granted, it usually lasts for three years, and you must start work within that period. If you are unsure whether your project needs permission, you can apply for a lawful development certificate to confirm that it is permitted development. Keep copies of all drawings, approvals and correspondence. A clear, well-prepared application is far more likely to be approved quickly, and it gives you confidence to enjoy your new space.