Permitted Development Rights 2026: What You Can Build Without Planning Permission

Planning a home extension? One of the first things you need to understand is whether you actually need planning permission — or whether your project falls under permitted development rights.

The good news: many extensions in England can be built without a planning application. The not-so-good news: the rules are surprisingly detailed, and getting them wrong can be costly. This guide explains exactly what permitted development rights allow you to do in 2026, what the limits are, and when you’ll need to apply regardless.

What Are Permitted Development Rights?

Permitted development (PD) rights are a set of rules built into national planning policy that allow certain types of work on your home without needing a formal planning application. They were created to reduce the burden on local councils for straightforward, low-impact projects.

PD rights are granted under the Town and Country Planning (General Permitted Development) (England) Order 2015 and have been updated several times since. The most significant recent change came through the Prior Approval Neighbour Consultation Scheme, which extended depth limits for single-storey rear extensions.

It’s also worth noting that PD rights apply in England only. Wales, Scotland, and Northern Ireland have their own versions of the rules — so if you’re in Cardiff or Swansea, the Welsh rules (under TAN 8 and PPW) apply, and limits differ slightly.

Permitted Development Rights 2026: The Key Rules for Extensions

Here are the current PD limits for the most common types of home extension:

Single-Storey Rear Extensions

• Detached houses: Up to 4 metres deep under standard PD. Up to 8 metres deep under the Prior Approval process (neighbour consultation scheme).
• Semi-detached and terraced houses: Up to 3 metres deep under standard PD. Up to 6 metres deep under Prior Approval.
• Maximum eaves height: 3 metres if within 2 metres of a boundary
• Maximum overall height: 4 metres
• Must not extend beyond the principal elevation (the front of the house)

Two-Storey Rear Extensions

• Maximum depth: 3 metres
• Must be at least 7 metres from the rear boundary
• Maximum height cannot exceed the original roof height
• Eaves and ridge must not be higher than the existing house
• Upper floor windows in a side elevation must use obscure glazing

Side Extensions

• Maximum width: half the width of the original house
• Maximum height: must not exceed the existing eaves and ridge
• Single-storey only on a side elevation in most cases
• Note: Side extensions are particularly likely to require planning permission in designated areas — see below

Roof Extensions and Loft Conversions

• Additional roof volume: up to 40 cubic metres for terraced houses, 50 cubic metres for detached and semi-detached
• No extension beyond the plane of the existing roof slope at the front
• Dormers must be set back from eaves by a minimum of 20cm
• No verandas, balconies, or raised platforms

If you’re looking at a loft conversion specifically, we’ve put together a detailed loft conversion guide here covering every type, cost, and what to expect from the process.

When Do Permitted Development Rights NOT Apply?

Even if your extension seems to fit within the limits above, there are several situations where PD rights are removed or restricted:

Listed Buildings

If your home is a listed building, PD rights don’t apply at all. Any extension — even a small one — will require both Listed Building Consent and full planning permission.

Designated Areas

Homes in the following designated areas have significantly reduced PD rights:

• National Parks (e.g. Snowdonia, Peak District)
• Areas of Outstanding Natural Beauty (AONBs)
• Conservation Areas — very common in towns and cities. Cladding changes, side extensions, and roof alterations often need permission.
• World Heritage Sites

If you’re in a conservation area, it’s always worth checking with your local planning authority before starting work.

Article 4 Directions

Councils can remove PD rights in specific streets or areas using an Article 4 Direction. These are often applied in historic residential areas to protect the character of the street. Your solicitor should flag these during conveyancing, but it’s worth checking on the Planning Portal if you’re unsure.

Previous Extensions

PD rights apply to the original house — meaning as it stood in 1948, or when it was first built if later. If previous extensions have already used up some of the PD allowance, you may have less remaining than you think. This catches a lot of people out, especially when buying and extending a home that’s already been altered.

Flats and Maisonettes

Permitted development rights for extensions only apply to houses, not flats or maisonettes. If you own a flat — even a ground-floor flat — you’ll need planning permission for any physical extension.

The Prior Approval Route: Extending Further Without Full Planning

If you want to extend beyond standard PD limits — up to 6 metres for semis or 8 metres for detached — you can use the Prior Approval Neighbour Consultation Scheme.

Here’s how it works:

• You notify the council of your proposed extension
• The council notifies your neighbours, who have 21 days to object
• If there are no objections (or objections are dismissed), Prior Approval is granted
• The process typically takes 4–8 weeks and costs around £120

This is a popular route for larger kitchen extensions and open-plan rear extensions that push beyond the standard 3m or 4m limits. It’s a lighter-touch process than full planning permission and is generally quite reliable where there are no major objections.

Do You Need a Lawful Development Certificate?

Even if your extension clearly falls within PD rights, many homeowners and their solicitors will ask for a Lawful Development Certificate (LDC). This is a formal document from the council confirming your extension was lawful — it’s not mandatory, but it’s useful evidence if you ever sell the property or face a challenge from a neighbour.

An LDC application costs around £103 in England and typically takes 4–6 weeks. It’s a sensible investment for any significant extension.

What About Building Regulations?

This is a common point of confusion. Permitted development is planning law — it has nothing to do with Building Regulations.

Almost every extension will require Building Regulations approval, regardless of whether it needed planning permission. Building Regs cover structural safety, fire safety, drainage, insulation, ventilation and more. You’ll need to submit either a Building Notice or Full Plans application to your local authority’s building control team (or use an Approved Inspector).

At Arkiplan, our service covers both sides: we produce all the drawings and documentation needed for your extension planning and building regs submissions, and we handle the applications on your behalf.

How to Check Your Permitted Development Rights

Here’s a simple checklist:

1. Check your title register — are there any planning conditions that restrict PD rights?
2. Check Planning Portal’s interactive guide — it steps through the rules clearly
3. Contact your local planning authority — most offer pre-application advice (sometimes free, sometimes a small fee)
4. Check if you’re in a conservation area or Article 4 Direction zone — your council’s website will usually show this on a map
5. Get professional drawings done — an architect or architectural designer can confirm your scheme is PD-compliant and prepare the documentation to prove it

Ready to Get Started?

Understanding permitted development rights is just the first step. Once you know what you can build, the next step is getting the drawings done and submitting the right applications.

At Arkiplan, we handle everything from initial design through to planning and building regulations approval — at a fixed price, with no hidden extras. We’ll tell you upfront whether your project needs full planning or can go the PD route, and we’ll manage the whole process for you.