Planning Atlas · Constraints
Constraint library.
A constraint is any designation that changes what you’re allowed to build on a piece of land. Conservation areas, listed buildings, green belt, flood zones, tree preservation orders, Article 4 directions. Most don’t stop development. They change the test your scheme has to pass, and often who decides it.
Every designation here is explained the same way: what it is, the statutory basis, what it actually restricts, and what it means in practice once you’re in front of a planning officer. Each one is mapped nationally from planning.data.gov.uk, so you can see where it falls, how much of England it covers and how much of that sits in London.
None of it is behind a login. Look up any site and we check it against all 23 layers at once.
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23
Layers mapped
national coverage
1,399,865
Designations in England
planning.data.gov.uk
71,899
Mapped across London
from our extracts
23
Written records
of 23 layers
Constraint records
Green BeltThe strongest land-use designation in the English planning system. Development in the Green Belt is inappropriate by definition — unless very special circumstances can be demonstrated.National constraint · NPPF Chapter 13 · 181 mapped in England→Conservation AreasAreas of special architectural or historic interest where the character must be preserved or enhanced. Designation doesn’t stop development — but it raises the bar, removes permitted-development rights, and gives objectors a statutory hook.Designated by LPAs · Planning (Listed Buildings & Conservation Areas) Act 1990 · 11,013 mapped in England→Listed BuildingsBuildings of special architectural or historic interest. Listing protects the whole building — inside and out — and any works affecting its special interest need listed-building consent, judged against a duty to preserve.Statutorily listed by Historic England · P(LBCA) Act 1990 · 382,258 mapped in England→Tree Preservation OrdersA TPO protects specific trees, groups or woodlands where their amenity value justifies it. Cutting down, topping, lopping or uprooting a protected tree without consent is an offence — and a constraint that quietly reshapes site layouts.Made by LPAs · Town and Country Planning Act 1990, s.198 · 102,574 mapped in England→Article 4 DirectionsAn Article 4 Direction withdraws specific permitted-development rights in a defined area — so works that would be permitted elsewhere need a full planning application. Common in conservation areas and over change-of-use rights.Made by LPAs · GPDO 2015, Article 4 · 7,327 mapped in England→Sites of Special Scientific InterestThe country’s best wildlife and geological sites. Development affecting an SSSI — or its hydrology and setting — triggers consultation with Natural England and a high bar where harm is likely.Notified by Natural England · Wildlife and Countryside Act 1981 · 4,128 mapped in England→Ancient WoodlandWoodland continuously present since 1600 — an irreplaceable habitat. NPPF gives it strong protection: loss or deterioration should be refused unless there are wholly exceptional reasons and a suitable mitigation strategy.Inventoried by Natural England · NPPF §186 · 44,373 mapped in England→Scheduled MonumentsNationally important archaeological sites. Any works affecting a scheduled monument need Scheduled Monument Consent from the Secretary of State — separate from, and additional to, planning permission.Scheduled by the Secretary of State · Ancient Monuments Act 1979 · 20,150 mapped in England→Heritage at RiskDesignated heritage assets whose condition is at risk through neglect, decay or vacancy. Sensitive, viable reuse is actively encouraged — these are the sites where heritage and development interests most often align.Identified by Historic England & LPAs · Heritage at Risk Register · 5,490 mapped in England→Flood Risk ZonesLand mapped by its probability of flooding from rivers and the sea, ignoring existing defences. Zone 2 is medium probability, Zone 3 high — and the higher the zone, the harder a residential scheme is to justify.National policy · NPPF Chapter 14 · Environment Agency mapping · 780,636 mapped in England→Air Quality Management AreasAreas a council has declared because national air quality objectives are not being met — almost always nitrogen dioxide from traffic. Declaring one obliges the council to act, and that obligation lands on new development.Statutory · Environment Act 1995, Part IV · 498 mapped in England→Archaeological Priority AreasAreas where there is a defined likelihood of buried archaeology. They do not stop development, but they put an evaluation and often a watching brief between you and a start on site.Local designation · NPPF Chapter 16 · Historic England (GLAAS in London) · 796 mapped in England→Special Areas of ConservationEurope’s strictest habitat protection, retained in domestic law. A scheme that could affect one — even from some distance — needs a habitats regulations assessment before permission can be granted.Statutory · Conservation of Habitats and Species Regulations 2017 · 260 mapped in England→Special Protection AreasSites classified for rare and migratory birds, protected on the same footing as Special Areas of Conservation. The test is the same: no adverse effect on integrity, assessed before permission.Statutory · Conservation of Habitats and Species Regulations 2017 · 88 mapped in England→Local Nature ReservesSites declared by a local authority for their local wildlife or geological value, and for people to enjoy nature close to home. Protection is national-policy based rather than absolute.Statutory · National Parks and Access to the Countryside Act 1949, s.21 · 1,727 mapped in England→National Nature ReservesThe country’s most important places for wildlife and geology, managed for nature first. Almost all are also SSSIs, so both regimes apply at once.Statutory · NPACA 1949 and Wildlife and Countryside Act 1981 · 225 mapped in England→National Landscapes (AONB)Landscapes designated for their national importance, renamed National Landscapes in 2023. Great weight goes to conserving their beauty, and major development is exceptional by policy.Statutory · Countryside and Rights of Way Act 2000, s.85 · 34 mapped in England→National ParksAreas with their own planning authority and their own statutory purposes. Conservation comes first, and where the purposes conflict, conservation wins.Statutory · Environment Act 1995 · NPACA 1949 · 10 mapped in England→World Heritage SitesPlaces of outstanding universal value. They are designated heritage assets of the highest significance, and the protection extends to their setting and to views towards them.International · UNESCO World Heritage Convention · NPPF Chapter 16 · 40 mapped in England→Locally Listed BuildingsBuildings a council has identified as locally significant without national listing. They carry no separate consent regime, but their significance is a material consideration and demolition is routinely resisted.Non-designated heritage asset · NPPF paragraph 209 · 448 mapped in England→Registered BattlefieldsSites of significant historic battles, registered for their historic interest. Designated heritage assets, where the significance lies in the ground and the terrain rather than in buildings.Designated heritage asset · NPPF Chapter 16 · Historic England register · 94 mapped in England→Brownfield LandCouncils divide suitable brownfield sites into two lists. Part 1 means the council considers the land suitable for housing. Part 2 goes further: the council has already accepted housing in principle, leaving the detailed design and technical matters to be approved.Statutory register · Town and Country Planning (Brownfield Land Register) Regulations 2017 · 37,505 mapped in England→Central Activities ZoneCentral London’s core of national and international activity. Inside it, the policy balance tilts away from ordinary housing and towards the commercial, cultural and civic functions that make the centre work.Strategic policy · The London Plan · 10 mapped in England→National counts are designations mapped in England on planning.data.gov.uk, checked 13 August 2026. London counts are those falling inside the GLA boundary, counted from the same data. What each designation does to a scheme’s chances is being computed now — it isn’t published here until it is checked.