What are planning constraints?
A planning constraint is a designation or restriction that changes what you can do with a property — sometimes requiring consent for work that would otherwise be automatic, sometimes shaping what gets approved. Knowing the constraints before you buy or draw up an extension saves the expensive kind of surprise.
The common constraints
- Conservation areas — extra controls on alterations, demolition and sometimes windows, doors and trees.
- Listed buildings — statutory protection; listed building consent is needed for most changes, inside and out.
- Tree preservation orders (TPOs) — consent needed to prune or fell protected trees.
- Article 4 directions — remove specific permitted development rights in a defined area, so normally consent-free work needs an application.
- Green belt — strong presumption against new development and large extensions.
- National Landscapes (AONBs) and national parks — tighter permitted development limits and design expectations.
- Flood zones — shape what can be built and may require flood risk assessments with applications.
- Scheduled monuments and archaeology — consent regimes of their own.
What a constraint means in practice
A constraint is rarely a ban. Most of the time it means extra consent, extra design conditions or reduced permitted development rights. The practical effect depends on the specific designation, the council's policies and the work you propose — which is why the answer that matters comes from the local planning authority, not from any dataset alone.
How to find the constraints on a property
- Screen early. The Address Lens planning constraints check screens the designations recorded around a postcode on England's Planning Data platform. The screening is England-only, postcode-centroid and indicative — it is not a parcel-level legal determination.
- Check the council. The local planning authority's website and planning register are the authoritative source for boundaries and directions.
- Rely on searches for the legal answer. The local authority searches your conveyancer runs (LLC1/CON29) reveal constraints as a matter of record before exchange.
Frequently asked questions
Do planning constraints stop me extending?
Not necessarily. Most constraints mean extra consent or design conditions rather than a ban — but some remove permitted development rights, so work that is normally consent-free needs an application. Confirm with the local planning authority before committing.
Will my conveyancer find planning constraints?
Yes — the local authority searches run during conveyancing (LLC1/CON29) are the authoritative route. Early screening is about surfacing questions before you are emotionally or financially committed.
How do I check if a house is in a conservation area?
Check the local planning authority's website or England's Planning Data platform, or run a screening check by postcode. Screening is indicative — confirm the boundary with the authority's own map.