London's Local Character and Density

For the first real time in London's history, we are seeing a major programme of densification across the city. The impact this development is having on the identity of London is profound. In central London, the setting of highly valued heritage assets is changing significantly. Outside the city's Central Activities Zone (CAZ), large Opportunity Areas (that is, predefined areas targeted for intensification in the London Plan) are introducing new typologies and urban characters adjacent to long-established neighbourhoods. In some instances, the planned change in character looks to be abrupt and is taking relatively little reference from existing adjacent areas.

Seeking to positively contribute to the debate over how London is developing, Historic England commissioned us to undertake a comprehensive mapping and study of London's historic character. This work sought to explore the potential conflicts emerging at all scales of planning and development, with a view to establishing a common assessment framework to steer more contextually-informed growth across London.

The historic evolution of London was used as the primary factor in the definition of character areas. These start with the original outline of Londinium, the Roman city, and then move outwards with each historic period of growth. Information about land use, density, infrastructure and street morphology was then used to establish a more nuanced interpretation of character.

A sequential process of cartographical analysis started with mapping the development and sprawl of London, mapping the urban footprint over time. Historic map sources such as the Hoefenagel map (1572), Davies map (1847) and Stanford map (1884) helped to form a base map. A second layer was then added on to this which adds greater detail to represent unique characteristics such as green spaces and the Green Belt, the legacy of the industrial revolution, infrastructure, waterways and the original high roads into and out of the city of London. Recognising that the London as we know and define it today is actually much larger than the original City, a third layer grafted on the towns, villages and settlements that grew up in the shadow of London only to become integrated into London itself over time.

The following character areas were identified: Londinium - the original Roman city later built over in the Medieval era; Georgian planning and growth; Victorian entrepreneurship and suburbs; the historic villages; former medieval market towns; suburban town centres that emerged with Victorian railway development; 20th century centres; 20th century suburbs; London's historic high roads; remnants of 19th century industry; waterways; the River Thames; the Green Belt; green open spaces; and Heathrow Airport. The footprints of each of these were overlaid onto a single map which provides a comprehensive and detailed picture of London's character.

The report recommends that a character-based approach should be incorporated into strategic policymaking with regard to local plan-making and the management of land use change and development proposals. This report illustrates that every character type in London can accommodate growth and that heritage assets can contribute positively to this. The mapping process could be a powerful tool for developing more contextually-aware urban design in the future.

The study's London-wide character map was adopted into the Draft London Plan first published by the Mayor of London in 2017. That same year, the study was awarded a RIBA President's Award for Research. It is also the genesis of Complex City, a forthcoming book to be published by the practice in 2020.