Why raw planning data is not enough
The government publishes planning constraints as open data, but it lists them as bare designations: "article-4-direction", "conservation-area", "tree-preservation-zone". If you are a homeowner wondering whether you can add a dormer, or a buyer working out a property's potential, that tells you almost nothing. This tool takes the exact same official data and does the missing step: it tells you what each constraint actually means for your plans.
That matters because the constraints on a property, not its size or price, often decide what you can do with it. An Article 4 direction can quietly remove your right to extend or change the windows. A conservation area restricts cladding, demolition and even some tree work. A tree preservation order makes pruning a garden tree a criminal offence without consent. Two near-identical houses on the same street can have completely different development potential, and this is how you see it before you spend money on plans or an offer.
Use it as a first look, not the final word
The data is official and national, but coverage depends on which councils have published which datasets, so treat a clear result as encouraging rather than a guarantee. Use this to learn what designations sit on an address and what questions to ask, then confirm the detail with the local planning authority or a planning consultant before you commit.
Planning your numbers too? Try the house prices by postcode tool, or check the Council Tax band for the address.
Frequently asked questions
What is a planning constraint?
A planning constraint is an official designation on land that changes what you can do to a property without permission. Common ones include conservation areas, listed buildings, Article 4 directions, tree preservation orders, green belt and flood zones. Each brings its own rules, so two identical houses can have very different development potential depending on the constraints on them.
Why does an Article 4 direction matter so much?
An Article 4 direction removes specific permitted development rights, the things you can normally do without planning permission. Where one applies, work such as an extension, a loft dormer, new windows, cladding or converting a house to a shared home (HMO) can suddenly need a full planning application. It is one of the most important and least understood constraints, which is why this tool flags it clearly.
If no constraints show, can I build freely?
Not necessarily. This tool reads the datasets that councils have published to the national planning data platform, and not every council has published every dataset yet. A blank result is encouraging but not a guarantee, so always confirm with your local planning authority before starting work or buying on the assumption you can extend.
Does this replace a proper planning search?
No. It is a fast, free first look that tells you which national designations sit on an address, so you know what questions to ask. A formal local authority search, and advice from a planning consultant or the council, is still essential before you commit to a project or a purchase.
Does it cover the whole UK?
The data covers England, which runs its planning constraints through a single national platform. Scotland, Wales and Northern Ireland publish their designations separately, so postcodes there are signposted to the right service rather than looked up here.
How current is the data?
It comes straight from the government planning data platform, which is updated as councils submit and revise their datasets. Designations like conservation areas change rarely, so it stays accurate, but for anything time-sensitive, check the official record linked next to each result.