Answer a few questions about your project to get an instant assessment. This tool covers England — Scotland, Wales and Northern Ireland have different rules.
When Do You Need Planning Permission in the UK?
Planning permission is required for any development — which under the Town and Country Planning Act 1990 means building operations, engineering works, mining operations, or material change of use of land or buildings. Not all works count as development, and many that do are automatically permitted under Permitted Development (PD) rights.
You will almost certainly need planning permission for:
A new dwelling or building on previously undeveloped land
Extensions that exceed Permitted Development limits (see below)
Converting a property from one use class to another (e.g. commercial to residential where not covered by PD)
Any works to a listed building that affect its special character (Listed Building Consent required)
Works in a conservation area where Article 4 Directions remove PD rights
Demolition of buildings above certain size thresholds
Target decision: 8 weeks from validation. Most straightforward extensions and outbuildings fall in this category.
Major Applications
Target decision: 13 weeks. Includes larger residential developments, commercial projects and anything requiring EIA screening.
Prior Approval
Decision within 42 days for larger home extensions. If no decision is given, Prior Approval is deemed granted.
Complex / Contentious
Can exceed statutory timescales. Major sites with objections, environmental concerns or legal agreements may take 6-18 months.
Permitted Development Rights: What You Can Build Without Planning Permission
Permitted Development (PD) rights allow many common home improvements without a formal planning application. These rights derive from the Town and Country Planning (General Permitted Development) (England) Order 2015 (as amended).
Single-Storey Rear Extensions (Class A)
Attached house: up to 3m deep from the original rear wall (or 6m under Prior Approval Neighbour Consultation Scheme)
Detached house: up to 4m deep (or 8m under Prior Approval)
Must not exceed the height of the original house or be within 2m of the boundary at more than 4m height
Materials must be similar in appearance to the existing house
Loft Conversions (Class B)
Additional volume: maximum 40m³ (terraced houses), 50m³ (semi-detached and detached)
No part of the extension to project beyond the existing roof slope on any elevation visible from a highway
Side-facing windows must be obscure-glazed
Building Regulations approval always required regardless of PD status
Outbuildings (Class E)
Can cover up to 50% of the garden (not counting the original house footprint)
Must not be forward of the principal elevation
Maximum eaves height: 2.5m; maximum overall height: 4m (dual pitch) or 3m (other)
Must not be used as a separate residential unit (dwelling)
Works NOT Covered by Permitted Development
Any extension on flats or maisonettes — these have no PD rights for extensions
Works that would extend beyond the original dwelling envelope on certain classified land (National Parks, AONBs, World Heritage Sites, Broads)
New buildings in front garden or on side of a corner plot visible from highway
Works requiring Listed Building Consent
Conservation Areas and Listed Buildings
Conservation areas and listed buildings carry significant additional restrictions that override standard Permitted Development rights in many cases.
Conservation Areas
In conservation areas, many standard PD rights are removed or restricted. Specific restrictions typically include:
Cladding the exterior with stone, artificial stone, pebble dash, render, timber, plastic or tiles requires permission
Side extensions are not permitted development in conservation areas
Outbuildings may have reduced PD rights
Permitted development for satellite dishes, solar panels and flues is more restricted
Listed Buildings
Listed Building Consent (LBC) is required for any works that would affect the special architectural or historic character of a listed building — both internally and externally. This is a separate process from planning permission and is free to apply for, though specialist heritage consultants are often needed. Works without LBC are a criminal offence.
Article 4 Directions
Local planning authorities can make Article 4 Directions to remove specific PD rights in defined areas. These are most common in conservation areas but can apply anywhere. Always check with your local council before assuming PD applies, particularly in sensitive areas.
How to Apply for Planning Permission
Check if you need it: Use the Planning Portal's interactive house tool at planningportal.co.uk or consult your local council's pre-application service.
Pre-application advice: For complex projects, a paid pre-app consultation (£50-£300) with the council can save time and money by identifying issues before a formal application.
Prepare drawings: You will need site location plan (Ordnance Survey map showing the application site), existing and proposed floor plans, elevations, and site sections. An architect or architectural technician can prepare these for £500-£2,000.
Submit the application: Online via the Planning Portal (planningportal.co.uk) or directly through your council's website. Pay the application fee at submission.
Validation: The council checks your application is complete. Missing information causes delays.
Consultation period: Neighbours are notified and have 21 days to comment. Statutory consultees (highways, environment, heritage) are also consulted.
Decision: A planning officer's report is produced and a decision made by delegated powers or planning committee. You will receive a Decision Notice.
Conditions: Permission is usually granted with conditions (materials, hours of working, drainage details, etc.) which must be complied with.
Retrospective Planning Permission
If works have been carried out without permission, you can apply for retrospective planning permission. The council assesses this on planning merit. If granted, the development is regularised. If refused, an enforcement notice will require demolition or alteration within a specified timeframe. It is always better to apply before building than to seek retrospective permission.
How much does planning permission cost in England in 2026?
A householder planning permission application in England costs £258 in 2026. Commercial applications cost £508. Prior Approval applications cost £120. Listed Building Consent is free to apply for. Scotland, Wales and Northern Ireland have different fee structures.
How long does planning permission take in the UK?
Minor householder applications should be decided within 8 weeks. Major applications take 13 weeks. Prior Approval decisions must come within 42 days. Complex or contentious applications involving legal agreements or Environmental Impact Assessment can take considerably longer.
What can I build without planning permission under permitted development?
Under permitted development rights in England you can typically build: a single-storey rear extension up to 3m deep (attached) or 4m deep (detached), a loft conversion within permitted volume limits (40m³ terraced, 50m³ other), outbuildings covering up to 50% of the garden area, and certain solar panels, porches, and satellite dishes subject to size and positioning rules.
Can I apply for planning permission retrospectively?
Yes. You can apply for retrospective planning permission after building has taken place. If granted, the development is regularised. If refused, the council can issue an enforcement notice requiring demolition or alteration within a specified period. Retrospective applications carry the same fee as standard applications.
What is the 4-year rule in UK planning?
The 4-year rule previously meant that after 4 years of unchallenged use or building operations, you could apply for a Lawful Development Certificate making the use lawful. However, recent legislative changes are extending enforcement periods. Always check current rules with your local planning authority as these provisions are subject to ongoing change.
What is an Article 4 Direction?
An Article 4 Direction is made by a local planning authority to remove specified permitted development rights in a defined area. This is common in conservation areas, National Parks, and Areas of Outstanding Natural Beauty (AONBs), requiring formal planning permission for works that would ordinarily be permitted development elsewhere.
Do I need planning permission for a loft conversion?
Most loft conversions are permitted development and do not require planning permission, provided the additional volume does not exceed 40m³ (terraced) or 50m³ (detached/semi), no part extends above the existing roof slope on the principal elevation, and materials match the existing house. Building Regulations approval is always required for a loft conversion regardless of planning status.
What is pre-application advice and is it worth it?
Pre-application advice is a paid consultation with your local planning authority before submitting a formal application. Costs range from £50 to £300+ depending on the council and project scale. It is highly recommended for complex or borderline projects as it gives an indication of likely success and any conditions, potentially saving the application fee and months of uncertainty.
MB
Mustafa Bilgic
Property and planning specialist with extensive experience covering UK planning law, permitted development rights and the planning application process for homeowners and small developers across England.