The Greater London Built-up Area, or Greater London Urban Area, is a

conurbation A conurbation is a region consisting of a number of metropolises, cities, large towns, and other urban areas which, through population growth and physical expansion, have merged to form one continuous urban or industrially developed area. In most ...

in south-east

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

that constitutes the continuous

urban sprawl Urban sprawl (also known as suburban sprawl or urban encroachment) is defined as "the spreading of urban developments (such as houses and shopping centers) on undeveloped land near a city". Urban sprawl has been described as the unrestricted ...

London London is the Capital city, capital and List of urban areas in the United Kingdom, largest city of both England and the United Kingdom, with a population of in . London metropolitan area, Its wider metropolitan area is the largest in Wester ...

, and includes surrounding adjacent urban towns as defined by the

Office for National Statistics The Office for National Statistics (ONS; ) is the executive office of the UK Statistics Authority, a non-ministerial department which reports directly to the Parliament of the United Kingdom, UK Parliament. Overview The ONS is responsible fo ...

. It is the largest urban area in the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...

with a population of 9,787,426 in 2011.

Overview

The Greater London Built-up or Urban Area had a population of 9,787,426 and occupied an area of at the time of the 2011 census. It includes most of the London region – omitting most of its woodland; small, buffered districts; the Lee Valley Park; and the two largest sewage treatment works serving London by the

River Thames The River Thames ( ), known alternatively in parts as the The Isis, River Isis, is a river that flows through southern England including London. At , it is the longest river entirely in England and the Longest rivers of the United Kingdom, s ...

. Outside the region's administrative boundary, it includes contiguous suburban settlements and a few densely populated outliers connected to it by ribbon development. Its outer boundary is constrained by the Metropolitan Green Belt and it is therefore much smaller than the wider metropolitan area of London. As a selective grouping of relatively low- to mid-density (and some high-density) output areas, each consisting of roughly 120 households, it can be compared to the London region, which covers and contained 8,173,194 residents at the time of the 2011 census. The built-up area of the Greater London region continues beyond the region's administrative boundary in some places, while stopping short of it in others. For this reason, the density of the Greater London Built-Up Area is 8.3% higher than that of Greater London, the figure for which includes these outlying rural areas (notably in

Hillingdon Hillingdon is an area of Uxbridge within the London Borough of Hillingdon, centred 14.2 miles (22.8 km) west of Charing Cross. It was an ancient parish in Middlesex that included the market town of Uxbridge. During the 1920s the civil pari ...

, Enfield, Havering and

Bromley Bromley is a large town in Greater London, England, within the London Borough of Bromley. It is southeast of Charing Cross, and had an estimated population of 88,000 as of 2023. Originally part of Kent, Bromley became a market town, charte ...

). All of both areas are drained ultimately by the

. The area uses around 4 gigawatts of electricity power.

History

The density gradient of industrialising cities has tended to follow a specific pattern: the density of the centre of the city would rise during urbanisation and the population would remain heavily concentrated in the city centre with a rapid decline in settlement towards the periphery. Then, with continued economic growth and the expanding networks of

public transport Public transport (also known as public transit, mass transit, or simply transit) are forms of transport available to the general public. It typically uses a fixed schedule, route and charges a fixed fare. There is no rigid definition of whic ...

, people (particularly the middle-class) would then slowly migrate towards the suburbs, gradually softening the population density gradient. This point was generally reached when the city reached a certain stage of economic development. In London, this point was reached in the first half of the nineteenth century, in

Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...

towards the end of the century and in

New York City New York, often called New York City (NYC), is the most populous city in the United States, located at the southern tip of New York State on one of the world's largest natural harbors. The city comprises five boroughs, each coextensive w ...

at the turn of the twentieth. However, London had been sprawling out of its medieval confines within the

City A city is a human settlement of a substantial size. The term "city" has different meanings around the world and in some places the settlement can be very small. Even where the term is limited to larger settlements, there is no universally agree ...

since the eighteenth century, when the city experienced its first great urban surge. Areas to the west of

Westminster Westminster is the main settlement of the City of Westminster in Central London, Central London, England. It extends from the River Thames to Oxford Street and has many famous landmarks, including the Palace of Westminster, Buckingham Palace, ...

were increasingly built up for the wealthy, to live in the suburbs of the city. A dramatic increase in the city's

began in the nineteenth century when labourers flocked from the countryside to work in the new factories that were then springing up. Large developments of small terraced houses began to appear and the new public transport systems – ( the Tube, buses and

tram A tram (also known as a streetcar or trolley in Canada and the United States) is an urban rail transit in which Rolling stock, vehicles, whether individual railcars or multiple-unit trains, run on tramway tracks on urban public streets; some ...

s) – allowed workers to commute into the city daily. Suburban districts also sprung up around the city centre to accommodate those who wanted to escape the squalid conditions of the industrial town. By the mid-nineteenth century, the first major suburban areas were springing up around

as the city (then the largest in the world) became more overcrowded and unsanitary. A major catalyst in the growth in urban sprawl came from the opening of the

Metropolitan Railway The Metropolitan Railway (also known as the Met) was a passenger and goods railway that served London from 1863 to 1933, its main line heading north-west from the capital's financial heart in the City to what were to become the Middlesex su ...

in the 1860s. The line joined the capital's financial heart in the City to what were to become the suburbs of

Middlesex Middlesex (; abbreviation: Middx) is a Historic counties of England, former county in South East England, now mainly within Greater London. Its boundaries largely followed three rivers: the River Thames, Thames in the south, the River Lea, Le ...

. Harrow was reached in 1880, and the line eventually extended as far as in

Buckinghamshire Buckinghamshire (, abbreviated ''Bucks'') is a Ceremonial counties of England, ceremonial county in South East England and one of the home counties. It is bordered by Northamptonshire to the north, Bedfordshire to the north-east, Hertfordshir ...

, more than from Baker Street and the centre of London. Unlike other railway companies, which were required to dispose of surplus land, the Met was allowed to retain such land that it believed was necessary for future railway use. Initially, the surplus land was managed by the Land Committee, and, from the 1880s, the land was developed and sold to domestic buyers in places like Willesden Park Estate, Cecil Park, near Pinner and at Wembley Park. In 1919, with the expectation of a post-war housing boom, Metropolitan Railway Country Estates Limited was formed and went on to develop estates at Kingsbury Garden Village near Neasden, Wembley Park, Cecil Park and Grange Estate at Pinner and the Cedars Estate at Rickmansworth and create places such as Harrow Garden Village. By the early twentieth century, amid increasing middle-class affluence, large low-density suburbs of semi-detached houses had sprung up all around the city, doubling the area of built-up London in the

interwar period In the history of the 20th century, the interwar period, also known as the interbellum (), lasted from 11 November 1918 to 1 September 1939 (20 years, 9 months, 21 days) – from the end of World War I (WWI) to the beginning of World War II ( ...

alone, even though the city's population only increased by 10% in the same time.

H. G. Wells Herbert George Wells (21 September 1866 – 13 August 1946) was an English writer, prolific in many genres. He wrote more than fifty novels and dozens of short stories. His non-fiction output included works of social commentary, politics, hist ...

even predicted in 1902 that within a hundred years most of southern England would have been subsumed into one gigantic

centred in London.

2011 Census subdivisions

At the time of the 2011 Census, the Office for National Statistics defined the Greater London Urban Area as being made up of the following components:

London region

The London region consists of 33 districts: the

City of London The City of London, also known as ''the City'', is a Ceremonial counties of England, ceremonial county and Districts of England, local government district with City status in the United Kingdom, city status in England. It is the Old town, his ...

, the 12 Inner London boroughs (including the City of Westminster), and the 20 Outer London boroughs. * Barking and Dagenham * Barnet * Bexley * Brent *

* Camden *

* City of Westminster *

Croydon Croydon is a large town in South London, England, south of Charing Cross. Part of the London Borough of Croydon, a Districts of England, local government district of Greater London; it is one of the largest commercial districts in Greater Lond ...

Ealing Ealing () is a district in west London (sub-region), west London, England, west of Charing Cross in the London Borough of Ealing. It is the administrative centre of the borough and is identified as a major metropolitan centre in the London Pl ...

* Enfield *

Greenwich Greenwich ( , , ) is an List of areas of London, area in south-east London, England, within the Ceremonial counties of England, ceremonial county of Greater London, east-south-east of Charing Cross. Greenwich is notable for its maritime hi ...

* Hackney * Hammersmith and Fulham * Haringey * Harrow * Havering *

Hounslow Hounslow ( ) is a large suburban district of West London, England, west-southwest of Charing Cross. It is the administrative centre of the London Borough of Hounslow, and is identified in the London Plan as one of the 14 metropolitan cen ...

Islington Islington ( ) is an inner-city area of north London, England, within the wider London Borough of Islington. It is a mainly residential district of Inner London, extending from Islington's #Islington High Street, High Street to Highbury Fields ...

* Kensington and Chelsea * Kingston upon Thames * Lambeth *

Lewisham Lewisham ( ) is an area of southeast London, England, south of Charing Cross. It is the principal area of the London Borough of Lewisham, and was within the Historic counties of England, historic county of Kent until 1889. It is identified in ...

* Merton *

Newham The London Borough of Newham () is a London boroughs, London borough created in 1965 by the London Government Act 1963. It covers an area previously administered by the Essex county boroughs of County Borough of West Ham, West Ham and County ...

* Redbridge * Richmond upon Thames * Southwark * Sutton * Tower Hamlets * Waltham Forest *

Wandsworth Wandsworth Town () is a district of south London, within the London Borough of Wandsworth southwest of Charing Cross. The area is identified in the London Plan as one of 35 major centres in Greater London. Toponymy Wandsworth takes its name ...

Surrey

* Addlestone * Ashford * Ashtead * Banstead * Bramley * Brookwood * Broomhall/ Windlesham/ Virginia Water * Caterham * Chertsey *

Chobham Chobham is a village and civil parishes in England, civil parish in the Surrey Heath, Borough of Surrey Heath in Surrey, England. The village has a small high street area, specialising in traditional trades and motor trades. The River Bourne ...

* Claygate * Cobham * Effingham * Egham *

Epsom Epsom is a town in the borough of Epsom and Ewell in Surrey, England, about south of central London. The town is first recorded as ''Ebesham'' in the 10th century and its name probably derives from that of a Anglo-Saxon settlement of Britain ...

Esher Esher ( ) is a town in the borough of Borough of Elmbridge, Elmbridge in Surrey, England, to the east of the River Mole, Surrey, River Mole. Esher is an outlying suburb of London, close to the London–Surrey border; with Esher Commons at its ...

* Ewell *

Guildford Guildford () is a town in west Surrey, England, around south-west of central London. As of the 2011 census, the town has a population of about 77,000 and is the seat of the wider Borough of Guildford, which had around inhabitants in . The nam ...

* Hooley *

Leatherhead Leatherhead is a town in the Mole Valley district of Surrey, England, about south of Central London. The settlement grew up beside a ford on the River Mole, from which its name is thought to derive. During the late Anglo-Saxons, Anglo-Saxon ...

* Lyne * Mimbridge * Molesey * Netherne-on-the-Hill * Ottershaw * Pirbright * Pirbright Camp * SheppertonIncluded under Walton-on-Thames subdivision * Staines-upon-Thames * Sunbury * Walton-on-Thames * Warlingham * Weybridge * Woking * Worplesdon

Hertfordshire

* Bedmond * Borehamwood * Bushey * Cheshunt * Chorleywood * Elstree * Hemel Hempstead * Hoddesdon * How Wood * Northwood * Park Street * Rickmansworth * Sawbridgeworth * Smallford * St Albans * St Margarets * Waltham Cross *

Watford Watford () is a town and non-metropolitan district with Borough status in the United Kingdom, borough status in Hertfordshire, England, northwest of Central London, on the banks of the River Colne, Hertfordshire, River Colne. Initially a smal ...

Berkshire

* Binfield * Bracknell * Cheapside * North Ascot * Winkfield Street * Woodside * Wraysbury

Essex

* Broadley Common * Chigwell *

Harlow Harlow is a town and local government district located in the west of Essex, England. Founded as a Planned community, new town in 1947, it is situated on the border with Hertfordshire, and occupies a large area of land on the south bank of the ...

* Loughton * Stapleford Abbotts * Waltham Abbey

Kent

Dartford Dartford is the principal town in the Borough of Dartford, Kent, England. It is located south-east of Central London and is situated adjacent to the London Borough of Bexley to its west. To its north, across the Thames Estuary, is Thurrock in ...

* Gravesend * Greenhithe * Maypole * Northfleet * Stone * Swanscombe

Omitted areas

In the 2011 census, the following areas were considered to be built-up areas but outside the Greater London Built-up Area, despite being within

Greater London Greater London is an administrative area in England, coterminous with the London region, containing most of the continuous urban area of London. It contains 33 local government districts: the 32 London boroughs, which form a Ceremonial count ...

. All of these areas had populations of less than a thousand except

New Addington New Addington is an area of South London, England, within the London Borough of Croydon. It is located 5 miles south east of Croydon and is adjacent to the Greater London boundary with Surrey. History Until the 1930s, the area now known as New ...

BUA and Harefield BUA which had populations of 22,280 and 6,573 respectively. Note that these are Built-up areas as defined by

and will have different boundaries from the settlements after which they are named. * Berry's Green * Crews Hill * Cudham * Downe * Harefield * Hazelwood *

* Royal National Orthopaedic Hospital

2001 Census subdivisions

At the time of the 2001 Census, the Office for National Statistics defined the Greater London Urban Area as being made up of the following components: