Permitted Development Rights for Householders: Classes A-G Explained with Conditions, Limits and Common Mistakes

Quick Answer: Permitted Development (PD) allows homeowners to make certain alterations without applying for planning permission, under the GPDO 2015. The main householder classes are A (extensions), B (roof alterations), C (other roof works), D (porches), E (outbuildings), F (hard surfaces), G (microgeneration). Each class has specific size, height, and positional conditions that must ALL be met — failing any single condition means PD does not apply and planning is required.

Summary

Permitted Development rights are statutory — they exist in law (the Town and Country Planning (General Permitted Development) (England) Order 2015, as amended). When a project meets all the conditions of a PD class, planning permission is not needed. When any condition is not met, planning permission is required regardless of how "minor" the works appear.

The most common mistake is treating PD as a vague "you can build this without planning" rule. PD is a precise set of conditions — each class has multiple conditions (A.1, A.2 etc.) all of which must be satisfied simultaneously. Miss one condition and you are not using PD.

PD rights can be removed or restricted by:

• Article 4 Directions — Local planning authority removes PD rights for specific areas (common in conservation areas, housing estates, and sensitive areas)
• Conditions attached to the original planning permission — Some new-build estates have conditions that remove PD rights for future alterations
• Listed building status — Listed Building Consent is required for works to a listed building, regardless of whether it is PD for planning
• Conservation areas — PD is more restricted in Conservation Areas for certain classes

Key Facts

• All PD conditions must be met simultaneously — A.1 AND A.2 AND A.3 etc. all apply at once. One failure = not PD.
• Measurements are from the "original" house — All size measurements refer to the house as originally built (or as it stood on 1st July 1948 if that is later). Previous extensions count towards the total.
• Certificate of Lawful Development — Apply to your LPA for a CLOPUD (Lawful Development Certificate for Proposed Use) to confirm PD status legally. Not mandatory, but strongly recommended.
• 10-year enforcement period — LPA can serve an enforcement notice for unauthorised PD breaches up to 10 years after the breach. After 10 years, the development becomes immune from enforcement.
• National Parks, AONBs, Conservation Areas — Reduced PD rights for extensions and roof works. Class B and C rights are restricted. Class A limits are smaller. Check specific restrictions.

Class A: Extensions and Alterations to the Dwellinghouse

The most frequently used class. Main conditions:

A.1 Conditions (size limits):

• Single-storey extension: total length from rear must not exceed 4m (detached) or 3m (semi/terraced). This is cumulative — if there is an existing extension, the new one plus the old one cannot exceed 4m/3m total from the original rear wall.
• Maximum height: 4m. Eaves height: ≤3m within 2m of a boundary.
• Extension must not be on a wall facing a highway.

A.2 Conditions (on designated land — conservation areas, AONB, National Parks):

• No side extensions (permitted on designated land only with planning)
• Cladding of exterior with stone, artificial stone, pebble dash, render, timber, plastic or tiles requires planning

Class B: Additions or Alterations to the Roof

Class B covers dormer windows and roof extensions. The 40–50m³ is the total cumulative addition — all previous PD roof additions count.

The dormer must not exceed the existing ridge height and must be set back 200mm from the eaves.

Class C: Other Alterations to the Roof

Covers reroofing, replacing tiles, adding skylights flush with the roof plane (Velux-type). Conditions:

• Materials must match existing roof materials in appearance
• Any roof extension must not extend beyond the outermost plane of the existing roof slope

Skylights that protrude above the roof plane (e.g., raised rooflights or lanterns projecting >150mm) do not fall under Class C but under Class A (for flat roof additions) — check projection limits.

Class D: Porches

External covered structures (porches) attached to the exterior of a dwelling:

• Maximum ground area ≤3m²
• Maximum height ≤3m
• Must not be within 2m of a boundary at the highway

Class E: Outbuildings and Curtilage Buildings

See outbuildings regs for full detail. Key conditions:

• Must be within curtilage of dwelling
• Must be ancillary use (not separate dwelling)
• Cannot be forward of principal elevation
• Height: ≤4m (dual pitch) or ≤3m (other); eaves ≤2.5m; within 2m of boundary: ≤2.5m overall
• No size limit for floor area under PD; only height limits

Class F: Hard Surfaces

Paving, driveways, and hard standing in the front of the dwelling:

• Any size permeable hard surface: PD
• Impermeable surface ≤5m²: PD
• Impermeable surface >5m²: planning required (unless drainage to soakaway or permeable area, or existing bound surface)

This catches almost all new front driveways/paving with solid concrete or tarmac. Permeable options (block paving with gaps, gravel, resin bound) are always PD.

Class G: Microgeneration

Solar panels, wind turbines, air source heat pumps under specified sizes are PD under Class G and Class H (now substantially updated). Key limits:

• Solar panels: no more than 200mm protrusion above roof plane; not on listed building or in World Heritage Site; standalone ground-mounted in garden ≤9m²
• Air source heat pump: one per dwelling; ≤0.6m³; ≥1m from property boundary; not on listed building; not in Scotland/Wales (have own regs)

Common Mistakes

1. Measuring from the extended house, not the original If the original rear wall was at 5m from the boundary, and a previous owner added a 2m extension, the current rear wall is at 3m from boundary. A new single-storey extension: you only have 1m of PD remaining (3m total from original rear wall – 2m already used = 1m).

2. Confusing PD with no-approvals-needed PD means no planning permission. Building Regulations, Party Wall Act, CDM, FENSA, and Part P still apply. Planning and Building Regs are different systems.

3. Height of extension within 2m of boundary Many people miss that eaves height must be ≤3m if the extension is within 2m of the boundary. A standard 2.6m internal height + 200mm floor + 200mm ceiling = 3m eaves. A full-pitch roof over 3m eaves is also restricted.

4. Prior Approval vs PD vs Planning Extensions 4–8m (detached) or 3–6m (other) under the Neighbour Consultation Scheme require Prior Approval, not full planning — but they are NOT automatically PD without the Prior Approval process.

5. Ignoring cumulative previous extensions If the house has had extensions before, check if they were PD or had planning consent. PD extensions count towards the cumulative limit; planning-consented extensions do NOT reset the PD allowance.

Frequently Asked Questions

How do I confirm my project is PD?

Apply for a Certificate of Lawful Development (CLD/CLOPUD) from your LPA. Cost is typically half the full planning fee (£103 for householder in England 2024). This is a legal document confirming PD status — important for mortgage lenders and conveyancers when selling.

If my PD extension is built incorrectly (too large), what happens?

The LPA can serve an enforcement notice up to 10 years after the breach. If the extension was built in breach of PD conditions, it is an unauthorised development. You may be required to demolish or modify. Retrospective planning consent (Lawful Development Certificate) may be possible if the project substantially meets PD conditions and the LPA is satisfied — but this is not guaranteed.

Do I need a Party Wall agreement if the extension is PD?

Yes — Party Wall Act 1996 and permitted development are entirely separate. If your extension involves work within 3–6m of a neighbour's foundations, or on or near a shared wall, you must serve Party Wall notices regardless of PD status.

Regulations & Standards

• GPDO 2015 (SI 2015/596) — Town and Country Planning (General Permitted Development) (England) Order 2015

• GPDO (Amendment) (No. 2) Order 2020 — Increases to rear extension PD limits (Prior Approval scheme)

• TCPA 1990 s.171 — Powers of enforcement for unauthorised development

• Building Act 1984 — Building Regulations apply separately to PD works

• Planning Portal — Permitted development rights for householders

• GPDO 2015 full text

• Planning Practice Guidance — Householder PD

• house extension process — Extension build process and timelines

• outbuildings regs — Class E outbuildings in detail

• planning permission — When full planning is required

• building control — Building Regulations vs planning permission