The Planning Dialect of Britain

What 4,556,475 UK planning application descriptions reveal about local words for buildings, extensions and places.

PlanningLens proposal-text analysis · 301 councils · counts frozen 9 September 2026 · first published 5 September 2026, corrected 9 September 2026

Correction, 9 September 2026: We corrected an extraction error affecting 14 London boroughs. This increases the readable corpus from 4,040,010 to 4,556,475 and changes some London rankings and shares, so the London section has been rewritten. Findings outside London, including all figures used in our 7 September press pitches, were unaffected. The error was in PlanningLens’s code, not council data.

Northern Ireland has sunrooms. England has conservatories.

Across the 285,296 readable planning application descriptions in Northern Ireland, “sunroom” appears 21.7 times per 1,000 and “conservatory” 5.4: roughly four sunrooms for every conservatory. In England outside London the order is reversed and then some, conservatory 34.2 per 1,000 and sunroom 1.7, about twenty conservatories for every sunroom. London barely writes the word at all (0.2 per 1,000). Scotland and Wales sit in between, conservatory country with a sunroom minority.

The five highest sunroom rates anywhere in the UK belong to Northern Irish councils: Lisburn & Castlereagh, Ards & North Down and Fermanagh & Omagh each write the word into more than 31 of every 1,000 descriptions, Mid & East Antrim and Antrim & Newtownabbey into 27 or more. The council in Great Britain that writes it most often is Edinburgh, 614 times, and even there that is 8 in every 1,000. This is not a handful of agents with a habit: Fermanagh’s 1,000 mentions come in 958 different wordings.

Coverage note: every rate on this page is per 1,000 application descriptions PlanningLens can read.

Scotland says attic. London says loft.

Scottish planning descriptions overwhelmingly favour “attic”: 8.9 mentions per 1,000 against 1.4 for “loft”. London overwhelmingly favours loft, 30.9 per 1,000 against 0.8 for attic. Edinburgh alone accounts for 2,250 attic mentions, a quarter of the UK’s, at 28.2 per 1,000 of its descriptions. Wales leans towards loft; Northern Ireland leans towards attic, far less strongly than Scotland. Whether an attic and a loft are always the same space is a question for architects; the record shows only which word each nation reaches for.

What is a cart lodge?

A garage, if you live in Suffolk.

In East Anglian planning applications a cart lodge is a detached, open-fronted garage, sometimes with a room over. The name is older than the car. Historic England lists cartlodges across Suffolk, the earliest surviving from the seventeenth century: timber-framed, open at both ends so a farm cart could be drawn straight through, sometimes with a loft above. PlanningLens found the word in 2,000 readable applications, 99% of them in England outside London and almost all of those in one corner of it: West Suffolk 642, Babergh Mid Suffolk 618 (nearly 3 in every 100 of its descriptions), South Norfolk 124, East Cambridgeshire 110, Maldon 86. Two Suffolk councils account for 63% of all the cart lodges in the UK. West Suffolk alone writes the word 613 different ways, so this is vocabulary, not a template.

Closet wing, back addition, outrigger

Three words London writes about the rear of its terraces, each with a home borough. In Kensington & Chelsea it is closet wing: 1,096 readable applications, 46% of all the closet wings in the UK. Westminster is second with 743, then Islington 281 and Camden 126. The wing itself is three hundred years old there: Museum of London Archaeology’s survey of 15 Cheyne Walk, a Chelsea house of about 1718, records an original closet wing at its rear. Across the boundary in Hammersmith & Fulham, and over the river in Wandsworth, it is back addition: 5,771 applications in Hammersmith & Fulham, 65% of the word’s readable mentions in the UK, and 2,531 in Wandsworth, roughly 8 in every 100 descriptions that borough receives. Nearly everywhere else in London it is outrigger. Ealing writes it most, 3,304 times, a fifth of the UK total, then Waltham Forest 1,693, Brent 1,136, Southwark 983, Islington 970, Hackney 912 and Haringey 897, though about half of Waltham Forest’s come from variants of one standard loft-extension phrasing, so its total measures a borough’s paperwork as much as its vocabulary. Whether the three words name the same piece of building is not something the record can settle; where each clusters, it can.

In Scotland you convert a steading and gate a pend

Start with the steading. In Scots it means the buildings of a farm, with or without the farmhouse, a word the Dictionary of the Scots Language traces to the fifteenth century; Burns used the word in a letter of 1789. Converting one is a planning genre: 885 readable applications, 95% of them Scottish, led by Angus (173), Perth & Kinross (138) and Dumfries & Galloway (131). England has 40.

Then the pend, the covered passage from the street through a building to the yard or back court behind: 98 Scottish applications, 38 of them Edinburgh’s, and 11 in the rest of the UK. The word began as the arch, not the passage. In older Scots to pend was to vault over, and the name slid from the vault to the way beneath it. Applications gate them, infill them and turn them into offices.

And the cottage flat, which sounds like a contradiction and is a building type: four homes under one hipped roof, the ground-floor pair entered from the front and the upper pair from the side. Historic Environment Scotland puts it in about three in ten of the schemes built under the 1919 “Homes fit for Heroes” Act. Officialdom calls the form four-in-a-block. The record does not: 104 applications say cottage flat, 5 say four-in-a-block.

The bothy has two lives. In Scotland it is the farm building where unmarried farm servants slept, a word in print by 1771, and Scottish applications use it at 0.6 per 1,000, eight times England’s rate. In England it is an estate word, the coach house and bothy, the former gardeners’ bothy, and Historic England lists kitchen-garden bothies at Mereworth Castle in Kent and at Newburgh Priory in Yorkshire, where the garden lads slept upstairs and the apples were stored below.

What is a mistal?

A cow house, if you are in West Yorkshire.

The Oxford English Dictionary has the word from a lease of 1583, as northern dialect, and the University of York’s Yorkshire Historical Dictionary has a 1731 record of “three Mistalls or Cow Houses”. PlanningLens found it in 19 readable applications once three house names had been set aside, and 17 of the 19 are in Kirklees, Calderdale and Bradford: barns and mistals converted to houses, a mistal turned into a holiday let, a cattle mistal demolished and replaced.

The North’s other word is the offshot, a projecting addition to a house, in these applications often at the back: 185 applications, led by South Tyneside (45), Sheffield (39) and Newcastle (22). The Tyne and Wear Historic Environment Record uses the word too, for the two-storey off-shots at the back of a Gosforth terrace of Tyneside-style flats; Edinburgh’s applications write outshot, a form the Scots dictionary has from 1709. And the shippon, Historic England’s cow-house word for the North West and the South West peninsula, appears 124 times, from the Lake District and the Staffordshire Moorlands to Dartmoor and Torridge.

The planning system itself has a dialect

Dwellinghouse.

One word, no space. It is the law’s word on both sides of the border: England’s permitted development order and Scotland’s both file householder rights under “development within the curtilage of a dwellinghouse”. One nation writes it as a matter of habit. Scottish applications use “dwellinghouse” 151 times per 1,000, against 13.5 in England outside London, 2.7 in Wales and 0.3 in Northern Ireland. Perth & Kinross writes it into 407 of every 1,000 descriptions, Dumfries & Galloway 399, Angus 273, Glasgow 224. England uses the one-word form far less often overall.

But some English councils write it at Scottish rates, and one London borough writes it more than any council in the UK. Brent uses the word in 503 of every 1,000 descriptions, 17,561 mentions, a higher rate than any Scottish council. Sheffield writes it 336 times per 1,000, Sefton 330, Wigan 198, Merton 132, Leicester 123 (though on only 571 readable descriptions), Hounslow 116 (12,633 mentions, more than any council in Scotland). Their neighbours write it at a fraction of those rates. Nothing in the law changes at the boundary; the house style does. Planning departments have dialects too, and this is the clearest one in the record.

In Gwynedd, almost half of planning descriptions contain Welsh

Codi annedd. Erection of a dwelling. In two Welsh councils the description field PlanningLens reads is bilingual. At least 49% of Gwynedd’s searchable descriptions and 28% of Ceredigion’s contain one of the eight Welsh planning terms tested (estyniad, adeilad, newid defnydd and annedd among them), usually beside the English: 17,821 applications between them. In the description field of the fifteen other Welsh authorities PlanningLens can read, those terms appear 6 times in total. The percentages are floors. The search looked for a short list of words, not for Welsh as a language, and it says nothing about what those councils publish in other fields or through other interfaces.

The words planning applications do not use

Britain’s most famous local words are for alleys, and the planning record hardly knows them. Across 4,556,475 readable descriptions, “ginnel” appears 25 times, scattered from Trafford to Leeds; Sussex’s “twitten” 20, eleven of them in Adur & Worthing; Hull’s “tenfoot” 8; Edinburgh’s “vennel” 12. Beyond them the record goes silent: snicket 1, jitty 1, drang 0, gennel 0. The hill-farm words fare no better: bastle 0, hogg house 0, hemmel 1, laithe 1, crog loft 2. And the Tyneside flat, a building type with its own entry in the region’s Historic Environment Record, 4.

Planning applications preserve a regional word when it names something people build, extend or convert: a steading, a cart lodge, a sunroom, a closet wing. They keep almost nothing of the words for the spaces people simply walk through. Ask the record what the alley behind the house is called and it has no answer. Ask it about the extension on the back, and it will tell you, often in a single word, which part of the country you are standing in.

Method

Data

Every word on this page, mentions by council (CSV)
Every word on this page, rates by nation (CSV)
The frozen data file behind this page (JSON)
PlanningLens methodology