You're right to treat planning as a quick-check thing by job type -- most grief comes from assuming "it's only a little job" when you've actually stepped outside permitted development.
Note: this guide covers England only. Planning rules differ significantly in Wales (separate GPDO), Scotland (Town and Country Planning (General Permitted Development) (Scotland) Order), and Northern Ireland (Planning (General Permitted Development) Order (NI)). If you're working outside England, check the relevant national planning portal and local authority.
7.17.1 Big picture
For houses in England, small-to-medium works often fall under permitted development (PD) rights in the GPDO 2015, so you don't need a full planning application. But:
- Rights only apply if the job meets all the conditions and limits in the Order.
- Conservation Areas, Listed Buildings and Article 4 Directions can remove or restrict those rights entirely.
- The Planning Portal's interactive house and mini-guides are the best quick reference for borderline cases.
Planning permission vs Building Regulations -- they're different things
Many trades and homeowners confuse these. They're separate:
- Planning permission -- controls what you build, where, how big, and how it looks from outside. Dealt with by the local planning authority.
- Building Regulations -- control how you build it: structure, fire safety, insulation, drainage, electrics, ventilation. Dealt with by building control (council or approved inspector).
You might not need planning permission but you almost certainly need Building Regs approval for extensions, loft conversions, structural alterations, and new drainage. Don't let "it's permitted development" trick you into thinking no approvals are needed at all.
7.17.2 Extensions (rear/side)
Usually covered by Class A, Part 1, GPDO.
Often no planning needed (permitted development) if, roughly
- It's on a house, not a flat/maisonette.
- Total added footprint (extensions + outbuildings) is within 50% of the original garden/curtilage.
- It doesn't go higher than the existing roof ridge.
- Single-storey rear: within depth and height limits -- up to 3m at eaves and 4m overall for standard PD.
- Side extensions are single-storey, modest in width, and not fronting a highway.
Larger home extension scheme (prior approval)
For single-storey rear extensions that go beyond the standard limits:
- Up to 6m deep for semi-detached and terraced houses.
- Up to 8m deep for detached houses.
- You apply for prior approval (not full planning) -- the council notifies adjoining neighbours who have 21 days to object. If no objections and the council doesn't raise issues, it's approved.
- This is not automatic PD -- there's a process and a fee, and neighbours do get a say.
You'll likely need full planning if
- It's a flat/maisonette or in some converted buildings -- PD rights don't normally apply.
- You're in a Conservation Area, National Park, AONB or World Heritage Site with tighter controls.
- An Article 4 Direction or planning condition has removed PD rights.
- You're over the size/height limits or pushing forward of the principal elevation facing a highway.
7.17.3 Loft conversions / roof extensions
Under Class B (roof enlargements) and Class C (other roof alterations).
Often permitted development if
- Additional volume is within:
- 40 m³ for terraced houses,
- 50 m³ for semis/detached.
- No part of the extension is higher than the existing roof ridge.
- Dormers don't project beyond the roof plane on the principal elevation facing a highway.
- Materials are similar in appearance to existing.
- Dormers set back at least 20 cm from eaves as per technical guidance.
Not permitted development / planning likely needed if
- On "designated land" -- Conservation Area, National Park, AONB, World Heritage Site -- many roof PD rights are restricted.
- It materially alters the front roof slope facing the street.
- Volume limits have already been used up by earlier roof additions.
7.17.4 Outbuildings (sheds, garden rooms, garages)
Covered by Class E, Part 1.
Often permitted development if
- Used for purposes incidental to the enjoyment of the house (store, home office, gym -- not a separate dwelling).
- Combined footprint of outbuildings + extensions is within the 50% curtilage rule.
- Single-storey, within height limits (typically up to 2.5m high within 2m of boundary, higher limits further in -- check guidance).
- Not forward of the principal elevation facing a highway.
Planning likely needed if
- It's in front garden, very tall, or effectively a separate dwelling (sleeping accommodation, kitchen).
- You're in a Conservation Area or Article 4 area restricting outbuildings.
Change of use warning
"Incidental to the enjoyment of the house" has a limit. If a garden room is being used as an Airbnb, a commercial office with employees visiting, or a separate rental unit, that's potentially a change of use requiring planning permission -- even if the building itself was PD. The same applies to garages converted to living space. The physical work might be PD, but the use might not be.
7.17.5 Fences, walls, gates and driveways
Most small boundary works are under Part 2 (Class A) and Part 1 (Class F) for hard surfaces.
Usually no planning needed if
- Fences/walls are up to 1m high next to a highway, or up to 2m elsewhere.
- Drives and hard standings use permeable materials (gravel, porous paving) or drain run-off to permeable areas within the property.
You'll likely need permission if
- Boundary treatment over the height limits.
- Drive/hardstanding in front garden over 5m² using impermeable surfacing draining to the road/sewer (SuDS rules).
- The property is Listed -- separate Listed Building Consent may be needed even for seemingly small changes.
7.17.6 Satellite dishes, antennas and solar panels
Satellite dishes and antennas
Covered by Class H (Part 1) and related GPDO provisions.
- Often permitted development if limited number and size of dishes, positioned to minimise impact.
- But rules tighten in Conservation Areas and on Listed Buildings -- check the interactive house and local guidance.
Solar panels
Solar on houses usually falls under separate PD rights for renewable energy.
- Roof-mounted domestic solar panels are often permitted development if they project only a small amount from the roof plane, are sited to minimise impact, and not above the highest part of the roof (excluding chimney).
- Ground-mounted have size, height and siting limits, and tighter controls in Conservation Areas.
- Always check current Planning Portal guidance -- solar rules have been tweaked several times.
7.17.7 Conservation Areas, Listed Buildings, Article 4 -- when the rules change
You must assume the rules are stricter if:
- The building is Listed -- many works that are PD elsewhere need Listed Building Consent, and some need planning too.
- You're in a Conservation Area, National Park, AONB or World Heritage Site.
- There's an Article 4 Direction in place -- the council has removed some or all permitted development rights for that area or street.
- Councils can also restrict permitted development via conditions on past planning permissions.
In these cases, "normally PD" is not safe -- you check with the local planning authority before promising anything to a client.
7.17.8 Lawful Development Certificate -- proving it's PD
If a client wants proof they don't need planning permission, or if you're dealing with a borderline case:
- You can apply for a Certificate of Lawful Development (Proposed) -- this is a formal confirmation from the council that the proposed work is lawful under PD rights.
- It costs less than a full planning application (current fee typically around £100-£200 for householder proposals).
- Once granted, it gives legal certainty -- useful for the client's records, for selling the property, and for your own protection.
- You can also apply for a Certificate of Lawful Development (Existing) if work has already been done and you need to prove it was lawful at the time.
This is the proper answer to "prove it's PD" -- not just "my builder said it was fine."
7.17.9 What happens if you get it wrong
If work is carried out without the required planning permission:
- The council can serve an enforcement notice requiring demolition, alteration or restoration of the unlawful work.
- There's a 4-year rule for operational development (building work) -- if the council doesn't take action within 4 years of completion, the work becomes immune from enforcement.
- There's a 10-year rule for change of use.
- But you can't rely on the 4-year rule as a strategy -- it's a backstop, not a plan. If the client gets an enforcement notice, they'll be looking at you as the builder who told them it was fine.
- Enforcement notices can be appealed, but appeals are expensive and uncertain.
- Unlawful work can also cause problems when the client tries to sell the property -- solicitors and mortgage lenders will flag it.
The safest position: if there's any doubt, check before you build.
What to do next
For any domestic job you're scoping:
- Use the Planning Portal interactive house and mini-guides for the specific project type (extension, loft, outbuilding, solar, etc.) as your first pass.
- Check if the property is Listed, in a Conservation Area, or under an Article 4 Direction using the council's website, then confirm with a quick email or call to the planning duty officer.
- Don't forget Building Regulations -- even if planning isn't needed, Building Regs almost certainly are for structural work.
- When it's borderline, steer the customer towards a short chat with the local planning department or a planning consultant, and don't start work until someone with planning competence has confirmed the route.
- For anything beyond straightforward, consider a Lawful Development Certificate for legal certainty.
That way you stay out of "builder told me I didn't need planning" territory and keep enforcement officers out of your life.
Sources
- Town and Country Planning (General Permitted Development) (England) Order 2015 -- legislation.gov.uk/uksi/2015/596/contents/made -- the GPDO: permitted development rights, conditions and limits.
- Town and Country Planning Act 1990 -- legislation.gov.uk/ukpga/1990/8/contents -- the main planning legislation for England and Wales.
- Planning (Listed Buildings and Conservation Areas) Act 1990 -- legislation.gov.uk/ukpga/1990/9/contents -- Listed Building Consent and Conservation Area controls.
- Town and Country Planning (General Permitted Development) (England) (Amendment) Order 2020 -- larger home extension scheme and prior approval provisions.
- Planning Portal technical guidance -- planningportal.co.uk -- interactive guides for each permitted development class.
- MHCLG / DLUHC permitted development guidance -- government technical guidance on PD rights interpretation.
Common questions
Do I need planning permission for a loft conversion?
Most loft conversions on a house fall under Permitted Development and don't need planning permission. Limits apply: up to 40m³ extra roof space (50m³ for detached/semi), no extension beyond the existing roof slope facing a highway, no balconies. Flats, listed buildings, and Conservation Areas always need full permission.
Planning Permission Checker tool.
What is permitted development?
Permitted Development Rights (PDR) are pre-approved planning rules that let you build certain works without permission. They cover certain extensions, outbuildings, and alterations under the Town and Country Planning Order 2015. Limits vary by property type and location. Get a Lawful Development Certificate to confirm in writing.
Planning Permission Checker tool.
What is a Lawful Development Certificate?
A formal document from your council confirming a building or use is lawful and doesn't need planning permission. It costs around £120 for proposed work, takes 8 weeks, and protects you from future enforcement. Buyers' solicitors regularly demand one when the property is sold.
Planning Permission Checker tool.
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