Property Research6 min read

What 1 Million Planning Constraints Reveal About England

We just finished mirroring every dataset on planning.data.gov.uk plus the new IMD 2025. Here is what one million constraints — listed buildings, AONBs, conservation areas, deprivation deciles — actually look like when you put them on the same canvas.


The Catalogue, in One Number


This week we finished a piece of slow, thankless infrastructure: mirroring every spatial dataset on planning.data.gov.uk into our own PostGIS database, alongside the brand-new MHCLG Index of Multiple Deprivation 2025 at LSOA level.


The total: 1,033,919 records across 30 datasets, plus 33,755 LSOAs, sitting next to the 28 million EPC certificates and 29 million Land Registry sales we already had.


It means a postcode lookup that used to bounce off four different live APIs now answers in 67 milliseconds with a single spatial query. More interestingly, putting it all on one canvas makes some old data look very different.


Here's what jumps out.


England Has 382,193 Listed Buildings


We always knew there were "around 400,000". Now we can put a number on each grade.


GradeCountWhat it means
Grade I9,343Exceptional national interest. ~2.4% of listings.
Grade II*22,112Particularly important. ~5.8%.
Grade II348,227National importance. ~91.1%.

If you're being shown a Grade I house, statistically it's rarer than a £10 note printed with a printing error.


The distribution by grade, drawn with bars:


Listings
Grade I9,343
Grade II★22,112▇▇
Grade II348,227▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇

It's a long tail — almost everything that's listed is Grade II. The "iconic-looking historic house" you imagine when someone says "listed" is most likely Grade II.


The Deprivation Map Has Hardly Moved


IMD 2025 published in March. The most-deprived Local Authority Districts are largely the same names that have topped the table every release since 2010. Our ten worst by share of LSOAs in deciles 1–2:


LADLSOAs in deciles 1–2Avg decile
Middlesbrough60.0%3.4
Manchester59.0%3.0
Blackburn with Darwen58.2%3.3
Sandwell56.3%3.1
Birmingham54.9%3.2
Blackpool54.3%2.8
Knowsley54.0%3.3
Nottingham53.6%3.2
Liverpool53.6%3.4
Hartlepool52.6%3.7

And the ten least-deprived:


LADLSOAs in deciles 9–10Avg decile
Wokingham78.6%9.2
Hart78.0%9.2
Surrey Heath72.7%8.6
Elmbridge69.5%8.6
Epsom and Ewell67.4%8.5
Fareham64.4%8.6
St Albans62.5%8.4
Rushcliffe62.3%8.6
Waverley58.5%8.5
Windsor and Maidenhead57.3%8.3

The North–South gap, in two tables.


Protected England Is a Lot of England


Think of it as concentric rings of legal protection. We pulled the count of distinct designations:


DesignationPolygons in dataset
Conservation areas11,094
Tree preservation zones75,695
Article 4 directions6,850
AONBs (now National Landscapes)34
National Parks10
Sites of Special Scientific Interest4,128
Ancient woodland44,373
Special Areas of Conservation260
Special Protection Areas88
Ramsar wetlands73
World Heritage Sites + buffers49
Heritage at Risk5,490
Air Quality Management Areas498

Add it up: a million distinct polygons telling you what you can and can't do with land in England. Most of them invisible to the buyer until they read a planning application refusal.


The Ten National Parks


For completeness — these are England's ten:


+Dartmoor
+Exmoor
+Lake District
+New Forest
+North York Moors
+Northumberland
+Peak District
+South Downs
+The Broads
+Yorkshire Dales

If your postcode falls inside one of these polygons, you live under the most restrictive planning regime in the country. Permitted development rights are largely stripped, even fence heights need consent.


And the 34 AONBs ("National Landscapes")


Slightly less restrictive than National Parks but still a major planning constraint. Worth knowing the list because the names crop up constantly in search descriptions:


Arnside & Silverdale, Blackdown Hills, Cannock Chase, Chichester Harbour, Chilterns, Cornwall, Cotswolds, Cranborne Chase & West Wiltshire Downs, Dedham Vale, Dorset, East Devon, Forest of Bowland, High Weald, Howardian Hills, Isle of Wight, Isles of Scilly, Kent Downs, Lincolnshire Wolds, Malvern Hills, Mendip Hills, Nidderdale, Norfolk Coast, North Devon, North Pennines, North Wessex Downs, Northumberland Coast, Quantock Hills, Shropshire Hills, Solway Coast, South Devon, Suffolk Coast & Heaths, Surrey Hills, Tamar Valley, Wye Valley.


What This Means When You're Buying


The reason any of this matters to a buyer:


1.A house in a conservation area is a different product to the same house 200 metres outside it. Window replacements, extensions, even paint colours can be controlled. That's a price input most websites just don't surface.
2.AONB and Green Belt act like a permanent supply constraint — they push prices up over decades because nothing can be built nearby.
3.An IMD decile is not a value judgement but it correlates with crime, schools, broadband, and price growth in ways that are predictable. We use it as one of ten inputs in our Investment Score.
4.A scheduled monument or heritage-at-risk entry within 250m of the property changes the planning calculus for any development on the road.

Up until last week, finding all of this required logging into seven different government portals and squinting at Esri map widgets. Now it's a postcode search for free, or a £14.95 PDF that bakes the lot into a single 14-page report.


How We Use This


Every paid Property Report now includes a "Planning & Constraints" page that lists every statutory designation the property is inside, with the polygon name where one exists. Conservation Area: yes/no/which one. AONB: which one. Article 4 direction: yes/no.


It's the same engine that runs the free postcode pages, just exposed at address granularity.


If you've been avoiding doing the planning research because it's tedious, this is what we built to remove the excuse.


→ Try it: search a postcode (free) · search an address (£14.95)


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