Quick answer
Search the local council's online planning register for the address and its neighbours: it shows applications, decisions and refusals.1 Then ask the seller for the building regulations completion certificate, or a competent person certificate, for any work.23 In England, councils can now take planning enforcement action for up to 10 years after building work was substantially completed (it was 4 years for work finished before 25 April 2024),45 and a building regulations notice can be given up to 10 years after completion.6
Key takeaways
- Planning records are held by the local council, usually on an online planning register.1
- Building regulations sign-off is separate from planning: look for a completion certificate.2
- Installers in a competent person scheme (for example windows, boilers, electrics) issue their own certificate.3
- Planning enforcement time limit in England: 10 years for work completed from 25 April 2024.45
- A lawful development certificate confirms an existing use or development is lawful.7
Most homes on the market have been altered at some point. The planning and building control records tell you whether that work was approved, and the register tells you what the neighbours are planning too. Both are searchable before you offer.
This guide covers England. Wales has the same planning register system, but its enforcement time limit for building work is still 4 years.
How do you search a property's planning history?
Planning applications are handled by your local planning authority, through the local council.1 Each council runs its own online planning register: search by address or postcode, and the results show the application, plans, decision notice and any conditions. Older records may only be available on request.
Search the house and the homes either side. Look for refused applications at the house (something the seller wanted but could not get), approved schemes that were never built (a permission you might use, if it has not expired), and large applications nearby, such as new housing or a change of use.
What to check for each piece of work
Match what you see on the viewing to the paperwork:
| Work | Planning | Building regulations |
|---|---|---|
| Rear extension | Permission, or permitted development within the size limits | Completion certificate |
| Loft conversion | Often permitted development, within limits; check Planning Portal | Completion certificate (fire safety, structure) |
| New windows or doors | Check first if the home is listed or in a conservation area | Competent person certificate or completion certificate |
| New boiler or rewiring | Not needed | Competent person certificate |
| Converted garage or outbuilding used as a bedroom | May need permission | Completion certificate |
Rules are simplified. Planning Portal and your council have the detail for each project.
Permitted development: what can be built without permission?
Houses (not flats or maisonettes) have permitted development rights. A single-storey rear extension can go up to 3 metres beyond the original rear wall, or 4 metres for a detached house, and no higher than 4 metres. Larger extensions of up to 6 metres, or 8 metres detached, need a prior approval application, and are not available in conservation areas and other designated land.8
Rights can be removed by a planning condition or an Article 4 direction, so a neighbour's extension is not proof that you can build the same. If you are buying to extend, check the planning register for conditions on the house, and consider a lawful development certificate for a proposed extension before you rely on it.7
What if work has no planning permission or sign-off?
In England, the time limit for planning enforcement on building work is 10 years from substantial completion, and 10 years for a change of use to a single home.4 That longer limit applies to work completed, or changes of use made, from 25 April 2024; earlier cases keep the old 4-year limit.5 So an extension finished in 2025 without permission can still face enforcement until 2035.
For building regulations, a notice to alter or remove work cannot be given more than 10 years after the work was completed.6 If there is no certificate, the seller can apply to the council for a regularisation certificate, which is available for work carried out after 11 November 1985.2 Sellers sometimes offer indemnity insurance instead; ask your conveyancer what it would and would not cover in your case.
Questions to ask the seller
Ask for the planning decision notice and the building regulations completion certificate for every extension, conversion and structural change, the installer's certificate for replacement windows, and the certificates for the boiler and any electrical work. The seller's property information form asks the same questions, so your conveyancer will follow up, but asking at the offer stage tells you early whether the price assumes paperwork that does not exist.
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Frequently asked questions
How can I see the planning history of a house?+
Search the local council's online planning register by address or postcode. It shows applications, plans, decisions and conditions for the property and its neighbours.
How long can a council take enforcement action for no planning permission?+
In England, 10 years from when building work was substantially completed, for work completed from 25 April 2024. Work finished before that date keeps the old 4-year limit.
Is building regulations approval the same as planning permission?+
No. Planning controls what you can build and how it is used; building regulations control how it is built. Most extensions and conversions need building regulations sign-off even when no planning permission is needed.
What if there is no completion certificate?+
The seller can apply to the council for a regularisation certificate for work done after 11 November 1985, or offer indemnity insurance. Ask your conveyancer which is appropriate.
Can flats use permitted development rights?+
No. Householder permitted development rights for extensions apply to houses, not flats or maisonettes.
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OfficialThe figures and rules on this page are drawn from the official UK government sources below. Rates are the confirmed 2026/27 amounts. Each link opens the relevant official page in a new tab.
- GOV.UK: Planning permission in England and Wales www.gov.uk/planning-permission-england-wales Contact the local planning authority through your local council.
- GOV.UK: Building regulations approval, how to apply www.gov.uk/building-regulations-approval/how-to-apply Completion certificate; regularisation for work after 11 November 1985.
- GOV.UK: Use a competent person scheme www.gov.uk/building-regulations-approval/use-a-competent-person-scheme Installer's certificate within 8 weeks; shows in solicitors' searches.
- legislation.gov.uk: Town and Country Planning Act 1990, section 171B www.legislation.gov.uk/ukpga/1990/8/section/171B England: 10 years for building operations and change of use to a single dwelling.
- legislation.gov.uk: SI 2024/452, regulation 5 www.legislation.gov.uk/uksi/2024/452/regulation/5/made The new limits do not apply to work completed or breaches before 25 April 2024.
- legislation.gov.uk: Building Act 1984, section 36 www.legislation.gov.uk/ukpga/1984/55/section/36 Notice cannot be given after 10 years from completion of the work.
- GOV.UK: Lawful development certificates www.gov.uk/guidance/lawful-development-certificates Certificates for existing and proposed uses or development.
- Planning Portal: Extensions, planning permission www.planningportal.co.uk/permission/common-projects/extensions/planning-permission Rear extension limits of 3m/4m, 6m/8m with prior approval; not for flats.
Verified against published UK government guidance. See also Methodology and Editorial standards.