How to find planning constraints before buying a house
A practical guide to checking planning constraints before you make an offer, so you know what restrictions apply and avoid costly surprises. Written for buyers in England, with notes for Wales and Scotland.
Checking a specific site?
Check a site free: your council, whether you are in a conservation area, and a basic flood check. The £9.99 site report covers everything else we can check.
Postcode, address or grid reference. England, Wales and Scotland. Free check, then the site report is £9.99, one-off.
When you are buying a house, it is easy to focus on the kitchen, the garden and the local schools. But planning constraints, the designations and policies that control what you can do with a property, can matter more to your long-term plans than any of those things.
A conservation area might stop you replacing the windows with double glazing. A flood zone could push up your insurance. Green belt might prevent the extension you had in mind. And a tree preservation order could mean that overgrown tree in the garden is staying put.
Most of this guide is about England. Where Wales or Scotland differ, it says so.
Step 1: Start with a free check
Before you book a viewing, check the site free. It shows which council covers the address, whether it is in a conservation area, and a basic flood check. The £9.99 site report (one-off) adds the rest, with the source for each finding. It covers everything we can check within 500 m of your pin, for 30 days. The report link never expires. See a sample report to see what it looks like.
- Open the site checker
- Type in the postcode or address
- Review the free result and what it says it couldn't check
- Open the site report for the detailed evidence
The site report includes checks for:
- Conservation areas
- Listed buildings
- Flood zones in England, the Flood Map for Planning in Wales and SEPA flood likelihood in Scotland
- Green belt (England, and Scotland where a council has supplied it; Wales has none)
- Tree preservation orders (in Scotland, where a council has supplied them)
- National Landscapes (formerly Areas of Outstanding Natural Beauty)
- SSSIs and other environmental designations
- Article 4 directions
- Scheduled monuments
This gives you a first picture before you spend anything on surveys or solicitors. It is a screening tool, not an official search. We show what we found, what came back clear, and where a source couldn't be checked. Some councils don't publish every dataset, so ask the council where it matters.
Step 2: Understand what each constraint means
Not every constraint is a problem. A conservation area might mean the street has great character, but it also means some permitted development rights are restricted. A flood zone might be manageable with the right insurance, but it affects your mortgage options.
A quick reference for England:
| Constraint | Key impact |
|---|---|
| Conservation area | Some permitted development rights removed; demolition often needs planning permission; trees protected by a six-week notice rule; higher design standards |
| Listed building | Listed building consent for any alteration affecting character, inside and out |
| Flood Zone 2 | Flood risk assessment for development; may affect insurance |
| Flood Zone 3 | Strict requirements for new development; insurance likely dearer; mortgage complications possible |
| Green belt | Strong presumption against new development; extensions must not be "disproportionate" |
| Tree preservation order | Cannot fell, prune or damage protected trees without consent |
| National Landscape (AONB) | Higher bar for development; some permitted development rights restricted |
| Article 4 direction | Specific permitted development rights removed, so check which ones |
| SSSI | Development that could harm the site is resisted; land management may be restricted |
| Scheduled monument | Scheduled monument consent for works; setting protected |
Step 3: Check the implications for your plans
If you plan to extend, convert or alter the property, match your plans against what you have found.
Want to extend?
- Conservation area: side extensions and larger rear extensions need planning permission
- Green belt: extensions must not be disproportionate to the original building
- Listed building: you need listed building consent as well as planning permission
- National Landscape (AONB): the larger home extension scheme under permitted development is not available
Want to convert or change use?
- Article 4 direction: it may remove the right to convert without planning permission
- Listed building: internal alterations need consent
- Conservation area: demolition of buildings above the size thresholds needs planning permission
Want to do garden or landscape work?
- Tree preservation order: protected trees cannot be touched without consent
- Conservation area: trees are protected by a six-week notice rule
- SSSI: significant changes near or on a SSSI may need consent or assessment
Step 4: Check the local plan
Beyond the constraints themselves, the council's local plan sets planning policy for the area. Check whether:
- The area is allocated for development, which could mean building nearby in future
- There are specific design policies for the area
- The council has an emerging plan that might change designations, such as a green belt review
The local plan is on your council's website, and the policies map shows designations on a map. In Wales, look for the local development plan and Planning Policy Wales. In Scotland, look for the local development plan and NPF4.
Step 5: Let your solicitor's searches confirm
When you make an offer and instruct a solicitor, they will order formal searches, usually after your offer is accepted. These include:
- Local authority search (CON29): the council's formal answer on planning designations, building control records, road schemes and other matters affecting the property
- Environmental search: flood risk, contaminated land and environmental designations
- Drainage search: water and sewerage connections and drainage risk
These give you formal confirmation, and they are what your lender and solicitor will rely on. But if you have done steps 1 to 4, nothing in them should come as a surprise. Planning Constraints is not a CON29 or an LLC1, and does not replace them.
Red flags to watch for
Some combinations deserve particular attention:
- Flood Zone 3, or inside the climate change extent: check insurance availability and cost before you commit
- Listed building and a wish to modernise: budget for traditional materials and specialist advice, and accept that some changes may not be possible
- Green belt and a wish to extend significantly: the disproportionate additions test may limit what you can do
- Several overlapping constraints: a property in a conservation area with listed status, TPOs and an Article 4 direction faces cumulative restrictions
Summary
Checking planning constraints before you buy protects you from costly surprises:
- Start with a free check: check a site free, then open the £9.99 site report for the detailed evidence
- Understand what each constraint means for your plans
- Check the local plan for policies and future changes
- Confirm through your solicitor's formal searches
The earlier you check, the better your position to negotiate the price, plan realistically and avoid commitments you cannot deliver on.
Check the site before your solicitor orders searches.
Searches are usually ordered after your offer is accepted. Check a site free first for your council, conservation area status and a basic flood check. The site report (£9.99, one-off) adds everything else we can check within 500 m of your pin, for 30 days.
We show what we found, what came back clear, and where a source couldn’t be checked. Some councils don’t publish every dataset, so ask the council where it matters. Planning Constraints is a screening tool, not an official local authority search or professional advice.