Most homeowners ask this question at exactly the wrong moment — usually when a builder has already started. The honest answer is that a large proportion of common home improvements in England do not require a formal planning application, because the government grants householders a pre-approved right to build within defined limits called Permitted Development (PD). Understanding where the PD boundary lies will save you time, money, and the risk of an enforcement notice.
This guide covers everything a homeowner in England needs to know: what triggers a planning application, how to check your own situation, what the application process involves, and the special rules that apply in conservation areas, listed buildings, and flats.
What Needs Planning Permission vs Permitted Development?
Projects that almost always need permission
- New dwellings — converting a large outbuilding into a separate dwelling, or building a new house in the garden
- Change of use — converting a house to flats, or turning a commercial building into residential use
- Extensions beyond PD limits — a rear extension deeper than 6 m on a semi-detached or 8 m on a detached; two-storey side extensions; extensions that cover more than 50% of the original curtilage
- Outbuildings beyond PD limits — any structure over 2.5 m high within 2 m of the boundary, or over 4 m (ridged) / 3 m (flat) further away; total coverage over 50% of the garden
- Roof extensions (mansard, most dormers) that face the highway
- Works to listed buildings — almost anything structural requires listed building consent, regardless of size
Projects that are usually Permitted Development
| Project | Typical PD limit (England) |
|---|---|
| Single-storey rear extension | Up to 6 m (semi) / 8 m (detached); max height 4 m |
| Two-storey rear extension | Up to 3 m from rear wall; must be at least 7 m from rear boundary |
| Loft conversion (dormer to rear) | Up to 40 m³ volume addition (semi/terrace); 50 m³ (detached); no highway-facing dormers |
| Outbuilding / garden office | Up to 2.5 m (within 2 m of boundary) or 4 m (ridged) further away; not forward of principal elevation |
| Porch | Up to 3 m² floor area; height under 3 m; no closer than 2 m to highway |
| Internal alterations | Removing non-load-bearing walls, new kitchens, bathrooms — no consent needed |
| Solar panels | On roof or in garden, within size and visual-impact rules |
Note: permitted development rights are the default in England but can be removed by an Article 4 Direction from your local council. This is common in conservation areas and some housing estates built under planning conditions that stripped PD rights. Always check your planning history.
How to Check Whether You Need Permission
- Look at your title deeds and existing planning permission — some properties carry conditions that restrict future development.
- Use the Planning Portal’s Interactive House (planningportal.co.uk) — it walks you through the most common project types with simple yes/no questions.
- Call your Local Planning Authority (LPA) — most councils offer a free pre-application discussion for straightforward householder queries.
- Apply for a Lawful Development Certificate (LDC) — this is a formal written confirmation from the council that your proposed works are lawful under PD or that no permission is required. It costs around £103 in England (2026) and takes up to 8 weeks. Estate agents and conveyancers routinely ask for one on sale; it is strongly advisable for anything at the edge of PD limits.
The Planning Application Process and Cost
If your project does require planning permission, the process in England is:
1. Pre-application enquiry (optional but recommended)
Most LPAs offer paid pre-application advice for householder projects — fees vary from free for small projects to £200–£500 for larger ones. This tells you informally whether a scheme is likely to get permission and what changes would improve its chances.
2. Prepare drawings
You will need (at minimum) a site location plan at 1:1250 and a site plan at 1:500 showing your property boundary, plus existing and proposed elevation and floor plan drawings. An architectural technologist or draughtsman will typically charge £600–£2,000 for householder drawings; an architect with full design input will charge more.
3. Submit the application
Householder planning applications are submitted via the Planning Portal. The fee in England (2026) is £258 for a householder application (works to an existing dwelling). Extensions and conversions generally fall in this category.
4. Validation and neighbour consultation
The LPA validates your application (usually 2–3 weeks), then places it on the public register and writes to neighbours. The consultation period is normally 21 days.
5. Decision
The statutory determination period for householder applications is 8 weeks. Most straightforward applications are decided within this period; complex ones can be extended by agreement. Around 88% of householder applications in England are approved.
| Stage | Typical duration |
|---|---|
| Pre-application advice | 4–8 weeks |
| Preparing drawings | 2–4 weeks |
| Validation | 2–3 weeks |
| Consultation | 3 weeks |
| Officer assessment and decision | 3–5 weeks |
| Total (planning only) | 14–24 weeks |
Conservation Areas, Listed Buildings and Flats
Conservation areas
If your home is within a designated conservation area, permitted development rights are significantly curtailed:
- Cladding the exterior in stone, render, timber or tile requires permission
- Most roof extensions visible from a highway need permission
- Satellite dishes on chimneys or front elevations need permission
- Demolition of buildings over a certain size needs Conservation Area Consent
The local council’s conservation officer is the key contact; most are willing to advise informally before you submit.
Listed buildings
A listed building designation (Grade I, II* or II) applies to the whole building including interior fixtures and fittings, and to any structure within the curtilage. Listed Building Consent is required for any works that affect its character — this runs in parallel with, and is separate from, planning permission. Unauthorised works to a listed building are a criminal offence. Always instruct a planning consultant or heritage architect before doing anything structural.
Flats and maisonettes
Permitted development rights do not apply to flats or maisonettes. If you own a flat, any external works — including replacement windows — will require planning permission. Internal works generally do not, but you must also check your lease, which may require freeholder consent for structural alterations.
Refusals and Appeals
If your application is refused, you have options:
-
Revise and resubmit — many refusals identify a specific reason (overlooking, bulk, materials) that can be resolved with design changes. A free resubmission is permitted within 12 months of a refusal for householder applications.
-
Appeal to the Planning Inspectorate — an independent planning inspector reviews the decision. Written representation appeals (the standard route for householder applications) typically take 24–36 weeks. You do not need a professional to submit a written appeal, but it helps. The appeal success rate for householder applications is approximately 30–35%.
-
Pre-application consultation with the officer — before appealing, contact the planning officer who decided your case and ask specifically what changes would have made the scheme acceptable. This often reveals a simpler path than appeal.
Key Points
- Permitted development covers most straightforward extensions, loft conversions and outbuildings within defined size limits — but check for Article 4 Directions that may have removed PD rights on your property.
- A Lawful Development Certificate provides written proof of PD compliance and protects you on resale.
- Householder planning applications cost £258 in England (2026) and take 8 weeks to decide.
- Conservation areas and listed buildings carry significant additional restrictions — always seek specialist advice.
- Flats have no PD rights; all external changes need full planning permission.
