Basement planning trends
The basement planning index stands at 44: the share of applications proposing a basement is less than half its 2016 level.
Basement applications since 2016
Basement applications in every 10,000 planning applications, over the 12 months to each month
How this is measuredA decade of decline
UK councils received 815 basement applications in the 12 months to September 2026, against 2,677 in 2016, when the share was highest. The share is 30% below three years earlier, and councils have received 18,085 basement applications since 2016.
A London habit
From 2023 to 2025 London received 82 basement applications in every 10,000, against 24 across the UK. Scotland was lowest at 3.3. Westminster leads all councils, with 972 since 2016. Of the top six, Hackney's share is highest, at 323 in every 10,000.
Q3 2026 against a year earlier
Councils received 160 basement applications in Q3 2026: 16 in every 10,000 applications, against 23 in Q3 2025, a share of all applications 32% lower than a year earlier.
Basement applications each quarter
160 in Q3 2026, against 249 a year earlier.
Out of every 10,000 applications
As a share of every application: 16 in every 10,000 in Q3 2026, against 23 a year earlier.
Where basement applications concentrate
By region
Basement applications in every 10,000 planning applications, 2023 to 2025
Councils with the most
Applications since 2016
-
Westminster
London · 161 in every 10,000 972 -
Barnet
London · 144 in every 10,000 780 -
Wandsworth
London · 209 in every 10,000 764 -
Hackney
London · 323 in every 10,000 750 -
Hammersmith & Fulham
London · 265 in every 10,000 570 -
Camden
London · 177 in every 10,000 521 -
Ealing
London · 96 in every 10,000 385 -
Lambeth
London · 127 in every 10,000 375 -
Brent
London · 94 in every 10,000 367 -
Haringey
London · 132 in every 10,000 342
Latest basement applications
- The Orsett Fruit Farm Orsett Road Horndon On The Hill Essex Erection of a single-storey rear orangery with basement accommodation accessed internally from the orangery, together with the construction of a new entrance porch to the front elevation of the existing dwelling.
- Orchard Lodge 16 Orchard Road Malvern Refurbishment, Alteration and Extension of the Existing Building (Currently Containing 5no. Flats) to Provide 9no. Flats (a Net Increase of 4no.), including Demolition of the Existing Rear Extension, Creation of a Basement Car Park, Widening of the Existing Vehicular Access and Associated Landscaping and Works
- 27 Kirkdale Road Harpenden Hertfordshire Two storey side and rear extension following the demolition of existing garage and conservatory, installation of air conditioning unit and solar panels, construction of basement (Part-retrospective)
- 4 Phillimore Gardens, London Internal reconfiguration of existing three self-contained residential units; construction of basement extension; erection of minor rear extension; partial demolition and reconstruction of existing garage; installation of lift shaft; replacement of modern windows with painted timber framed sash windows; repair and restoration of external period features; including cornices and cast iron rain water goods; and associated external alterations.
- Orchard Corner Netherhall Gardens London Demolition of the existing side extension, rear extension and garage, erection of a two storey side extension and single storey rear extension, excavation to create basement with associated side and rear, loft conversion with associated external alterations and associated works.
- 84 Barton Drive Newton Abbot Devon Conversion of basement to kitchen/dining room, internal & external alterations and formation of new side extension with terrace
Questions
How many basement planning applications are there in the UK?
Councils have received 18,085 since January 2016, 815 of them in the 12 months to September 2026. Their share peaked in the 12 months to December 2016.
Which councils receive the most basement applications?
Westminster, Barnet and Wandsworth have received the most since 2016.
Are basement applications rising or falling?
Falling. The basement planning index stands at 44, less than half its 2016 share, and the share in the 12 months to September 2026 was 30% below three years earlier.
About Plota
Plota is the UK's most visited planning search, according to Similarweb. It shows every new planning application from every UK council, read daily from 390 planning registers, with past applications back to 2016 from more than 420 registers, including those of councils since merged. It also covers planning committee decisions, HMO licences and premises licences.
How this is measured
What needs an application
Kensington and Chelsea limited most new basements to a single storey in January 2015, after its basement applications rose from 46 in 2001 to 450 in 2013.
Methodology
- What is counted: planning applications to UK councils whose description names basements or a close variant of the words, by the date each council received them. These are planning applications, not completed schemes; the largest energy and infrastructure projects are consented nationally rather than by councils, so they sit outside these counts.
- How matches are checked: we read the 200 most recent basement applications and 20 from every year since 2016 to confirm each one belongs.
- Topic counts leave out, by design, works to trees and applications that only discharge conditions, amend an earlier permission or approve reserved matters, which follow a scheme already counted. Everything else is counted.
- A share is the number out of every 10,000 applications over the previous 12 months. Each topic is a number in every 10,000 planning applications, so trends compare when overall planning activity changes; the share still moves when either the topic's count or the total does. The basement planning index sets the 2016 share at 100, so 200 means twice as common as in 2016.
- Source: the planning registers of every UK council, January 2016 to September 2026, read on 9 November 2026.
- Planning is seasonal, so each quarter is compared with the same quarter a year earlier.
- Year on year: each topic's and theme's share of all applications in Q3 2026, against Q3 2025, at every council we hold. A share is the number in every 10,000 applications. Shares compare across councils and years; raw counts do not.
- Left out of the topic shares: Birmingham's applications from June to September 2026: a validation backlog at the council since June 2026: of 685 reference numbers it issued in September, its register lists 288. The same months a year earlier are left out too, so every comparison covers the same councils.
- Download the data (CSV): every topic and theme, each quarter since 2016.
Sources
- Kensington and Chelsea adopted Policy CL7 on 21 January 2015, limiting basement depth to a single storey in most cases and excavation to half a garden, after its basement applications rose from 46 in 2001 to 450 in 2013. rbkc.gov.uk