Planning Permission FAQ

It depends on the type and scale of your project. Many home improvements fall under 'permitted development rights', meaning you don't need to apply. However, if your property is in a Conservation Area, is a listed building, or is in the Green Belt, your rights may be more limited. Extensions, loft conversions, and outbuildings often fall within permitted development if they meet certain size and height limits. Use our Planning Advisor to get an instant assessment for your specific project.

Permitted development rights are a set of automatic planning permissions granted by Parliament under the Town and Country Planning (General Permitted Development) (England) Order 2015 (as amended). They allow certain types of work to be carried out without needing to submit a planning application. This includes many types of home extensions, outbuildings, solar panels, and some changes of use. However, these rights come with conditions and limits on size, height, and materials. They can also be removed by Article 4 Directions or if your property has specific designations.

Planning permission is about whether you CAN build — it controls what development is appropriate in terms of land use, appearance, and impact on neighbours and the environment. Building regulations are about HOW you build — they set minimum standards for the design and construction of buildings to ensure safety, energy efficiency, and accessibility. You may need one, both, or neither depending on your project. For example, a small rear extension might not need planning permission (permitted development) but will still need building regulations approval.

Planning application fees are set nationally by the government. As of 2024, common fees include: Householder applications (extensions, alterations) — £258; Full planning applications for new dwellings — £578 per dwelling; Change of use — £578; Lawful Development Certificate — £129 (half the normal fee); Listed Building Consent — Free. Fees are doubled in England compared to pre-2023 levels. Additional costs may include drawings, surveys, reports (ecology, heritage, flood risk), and professional fees if you hire an architect or planning consultant. Using PlanWise can help you understand what's needed before you spend on professionals.

Statutory timescales for planning decisions are: Householder applications — 8 weeks; Minor applications — 8 weeks; Major applications — 13 weeks; Applications requiring an Environmental Impact Assessment — 16 weeks. In practice, many councils take longer due to backlogs. You may also need to factor in pre-application advice (2-6 weeks), preparing your application (1-4 weeks), and any subsequent amendments. Lawful Development Certificates typically take 8 weeks. Prior approval applications take 56 days (8 weeks) from the date the council receives the application.

You can absolutely apply for planning permission yourself — there is no legal requirement to use an architect or planning consultant. The Planning Portal (planningportal.co.uk) provides a standard application form. However, you will need accurate drawings (existing and proposed plans, elevations, and a site plan), and for complex projects, professional drawings can significantly improve your chances of approval. PlanWise helps you understand the requirements before you decide whether to engage a professional.

In most cases, a single-storey rear extension falls under permitted development if it meets these conditions: it extends no more than 4 metres from the rear wall (or 3 metres for a semi-detached/terraced house), maximum height is 4 metres, eaves height is no more than 3 metres, it doesn't cover more than 50% of the garden, and it uses materials similar to the existing house. Under the 'larger home extension' scheme, detached houses can extend up to 8 metres and semi/terraced up to 6 metres, but this requires a prior approval notification to the council. Restrictions apply in Conservation Areas, AONB, and for listed buildings.

Most loft conversions fall under permitted development for houses (not flats or maisonettes). The key limits are: the volume added must not exceed 40 cubic metres for terraced houses or 50 cubic metres for detached/semi-detached houses; the extension must not be higher than the existing roof; materials should be similar in appearance; no verandas, balconies, or raised platforms; side-facing windows must be obscure-glazed and non-opening below 1.7m; the roof enlargement must not extend beyond the existing house wall on the front elevation. Rear dormers are generally acceptable but may need planning permission in Conservation Areas.

Garden rooms and outbuildings (sheds, summerhouses, studios) are usually permitted development if they are: single storey with maximum eaves height of 2.5m; maximum overall height of 4m (dual pitched) or 3m (any other); not in front of the principal elevation; more than 2m from any boundary if over 2.5m high; covering no more than 50% of the garden; not used as a separate dwelling. In Conservation Areas, additional restrictions apply and outbuildings over 10 sqm may need planning permission. If your garden room will include sleeping accommodation or a kitchen, you may need planning permission.

Converting an existing integral or attached garage into a habitable room (home office, gym, bedroom) usually does not require planning permission, as it's considered an internal alteration. However, you should check: any conditions attached to the original planning permission (some require garages to be retained for parking); whether your property has an Article 4 Direction that restricts changes; local parking policies that may resist the loss of off-street parking. You will almost certainly need building regulations approval for the conversion. If you're changing the garage door to a wall with a window, this may need planning permission if it faces a highway.

Solar panels are permitted development on most houses if: they don't protrude more than 200mm from the roof surface; they don't project above the highest part of the roof (excluding the chimney); on flat roofs, they are no more than 1m above the highest point of the roof; the panels are not installed on a listed building or within the curtilage of a listed building. In Conservation Areas, AONB, National Parks, and World Heritage Sites, panels must not be fitted on a wall or roof slope that faces a highway. Standalone ground-mounted panels must be no more than 4m high and 9 sqm, and not within 5m of the property boundary.

A 'change of use' occurs when a building or land is used for a materially different purpose. The Use Classes Order (2020) categorises uses into classes: Class E (commercial, business and service), Class F1 (learning and non-residential institutions), Class F2 (local community), Class C (residential, including C1 hotels, C2 care homes, C3 dwellings, C4 HMOs), and Sui Generis (unique uses like pubs, hot food takeaways, cinemas). Changes within the same use class don't usually require planning permission. Some changes between classes are permitted under the GPDO (e.g., Class E to C3 residential via prior approval Class MA).

Yes, in many cases. Under Class MA of the GPDO (which replaced Class O in August 2021), you can convert Class E commercial premises (offices, shops, restaurants, etc.) to residential (C3) through a prior approval process. Key conditions: the building must have been in commercial use for at least 2 continuous years; it must have been vacant for at least 3 continuous months; there is a maximum of 1,500 sqm per application; the council will assess transport, contamination, flooding, natural light, fire safety, noise, and the impact on local services. A prior approval application fee is £120 per dwelling.

Yes, under Class Q of the GPDO, you can convert agricultural buildings to residential dwellings through prior approval. Key requirements: the building must have been in agricultural use on 20 March 2013 (or last in agricultural use before that date); the site must be on an established agricultural unit; a maximum of 5 dwellings (and no more than 465 sqm of floor space) can be created; the building must be structurally capable of conversion without substantial rebuilding; the council assesses transport, noise, contamination, flooding, location, and design. This is one of the most common barn conversion routes but has strict structural requirements.

A Conservation Area is an area of special architectural or historic interest, designated by the local planning authority under Section 69 of the Planning (Listed Buildings and Conservation Areas) Act 1990. In Conservation Areas: permitted development rights are more restricted (e.g., no rear dormers, cladding, satellite dishes visible from the highway); you need Conservation Area consent for demolition; trees are protected (6 weeks' notice required before works); new development must preserve or enhance the character and appearance of the area. You can check if your property is in a Conservation Area using our Property Checker.

If your property is a listed building (Grade I, II*, or II), you need Listed Building Consent for any works that affect its character as a building of special architectural or historic interest. This includes internal AND external alterations — even minor changes like replacing windows, painting over original features, or removing internal walls. Permitted development rights for listed buildings are severely restricted. Carrying out work to a listed building without consent is a criminal offence. Listed Building Consent applications are free. You should engage a heritage consultant for significant works.

The Green Belt has the strongest protections against inappropriate development. Under NPPF paragraphs 152-153, inappropriate development in the Green Belt should not be approved except in 'very special circumstances'. However, certain types of development are not considered inappropriate, including: replacement of a building (provided it is not materially larger); limited extension or alteration of an existing building; limited infilling in villages; agricultural buildings; outdoor sport and recreation facilities. Extensions in the Green Belt are typically limited to a proportionate increase — many councils apply a 30-50% volume increase limit.

PlanWise offers three main tools: (1) The Planning Advisor — describe your project in plain English and get instant, AI-powered guidance based on current UK planning regulations, including the NPPF and GPDO; (2) The Property Checker — enter your address to check 13+ planning constraint datasets (conservation areas, listed buildings, green belt, flood zones, etc.) and view previous planning applications from 425 UK authorities; (3) The Mock Application — submit a mock planning application and receive a simulated officer assessment with approval likelihood, policy compliance analysis, and suggestions.

PlanWise is designed to give you a strong starting point — it helps you understand your planning position, know your rights, and make informed decisions before engaging a professional. For straightforward projects (extensions, outbuildings, change of use), PlanWise may provide all the guidance you need. For complex projects (major developments, sites with multiple constraints, listed building works), we recommend using PlanWise to understand the issues and then engaging a qualified planning consultant or architect with the knowledge PlanWise has given you. This can save you significant time and money in professional fees.

PlanWise uses multiple authoritative data sources: (1) Planning constraint data comes from planning.data.gov.uk — the official UK government planning data platform, provided under the Open Government Licence v3.0; (2) Planning application history comes from PlanIt, which aggregates data from 425 UK planning authorities covering 20.2 million+ applications; (3) Our AI guidance is based on the National Planning Policy Framework (NPPF), the General Permitted Development Order (GPDO), the Use Classes Order, and relevant planning practice guidance.