Radial city plan
![]() |
Early concentric cities in Europe often came in the form of settlements built within castle walls. Trelleborg is one of these ancient sites, located in Denmark near Slagelse on the isle of Seeland. |
Contents |
[edit] Introduction
A radial city plan (also referred to as a radial urban plan or radial concentric city plan) is an urban planning approach, that, instead of using a traditional rectangular grid, is based on a series of concentric circles. An important community or commercial building (or collection of buildings) is sometimes placed at its centre. Roads radiate out from the centre linkin ring roads.
Some cities are completely radial, while others only incorporate this approach in certain neighbourhoods or areas of the city. This can be due to limitations such as topography, zoning, geography, existing buildings and roads and so on.
[edit] History
Radial city planning goes back to ancient times. Early cultures used the circular configuration to bring together the community while keeping out invaders. One early European example of radial city planning is the Danish settlement of Trelleborg. Situated within a circular Viking castle, the city of more than 1,000 people was occupied from approximately 980 AD to 1050 AD.
[edit] Circleville, Ohio
The concentric circle city model was used in many parts of the world even before Trelleborg. Over the centuries, some cities that started with radial plans made the change to rectangular grids.
In the early 1800s, the US town of Circleville, Ohio was planned and built over prehistoric circular earthworks. The courthouse was placed in the centre of the town’s radial plan.
In just a few decades, the radial plan had become unpopular and was considered ‘peculiar’. At this point, a conscious decision was made to convert the town plan from circular to rectangular. By 1856, the city’s Circleville Squaring Company had successfully redeveloped the town to remove its radial past.
![]() |
This overhead map of the city of Circleville, in Pickaway County, Ohio, is from 1876 - after its concentric circle plan had been entirely replaced by a grid. The town kept its name despite the drastic change in its configuration. |
[edit] Circular garden cities
As early as 1820, the landscape architect John Claudius Loudon envisaged cities as concentric rings of buildings interspersed with open green areas. In the late 1800s, Sir Ebenezer Howard built on Loudon's idea by incorporating the radial approach into his proposed garden cities. As a self-sufficient combination of living space, industry, agriculture and leisure, Howard’s garden cities used concentric circles connected by radial roads. Parks and other open spaces would be placed in strategic areas to support the community.
Once capacity was reached in the original community, a new garden city could be built nearby. This would not only help to reduce overcrowding and slums, it would create community clusters that could be connected through public infrastructure.
![]() |
Sir Ebenezer Howard's idealised garden city incorporates concentric radial cities linked by railways and roads. |
[edit] Basic requirements of a radial city plan
The success of circular cities (like the garden cities developed by Howard) is based on essential factors, including:
- Geography - the natural geography of the site should be able to accommodate suitable outward growth.
- Topography - the land should be flat, open and free from drastic changes that could cause obstructions to development.
- Ideology - the developers, overseers and occupants should understand (and ideally embrace) the philosophy of a radial city plan and be prepared to adhere to the principles behind it - regardless of possible restrictions to economic development and growth.
[edit] Related articles on Designing Buildings Wiki
- Brasilia Syndrome.
- Collaboration needed to deliver national and regional transport strategies.
- Compact sustainable city.
- Densification.
- Garden cities.
- Garden communities and the historic environment.
- Garden suburb
- London Cycle Network.
- Piazza.
- The green belt and historic buildings
- Town and Country Planning Association TCPA
- Town planning.
- Urban design.
Featured articles and news
Ebenezer Howard: inventor of the garden city. Book review.
The Grenfell Tower fire, eight years on
A time to pause and reflect as Dubai tower block fire reported just before anniversary.
Airtightness Topic Guide BSRIA TG 27/2025
Explaining the basics of airtightness, what it is, why it's important, when it's required and how it's carried out.
Construction contract awards hit lowest point of 2025
Plummeting for second consecutive month, intensifying concerns for housing and infrastructure goals.
Understanding Mental Health in the Built Environment 2025
Examining the state of mental health in construction, shedding light on levels of stress, anxiety and depression.
The benefits of engaging with insulation manufacturers
When considering ground floor constructions.
Lighting Industry endorses Blueprint for Electrification
The Lighting Industry Association fully supports the ECA Blueprint as a timely, urgent call to action.
BSRIA Sentinel Clerk of Works Training Case Study
Strengthening expertise to enhance service delivery with integrated cutting-edge industry knowledge.
Impact report from the Supply Chain Sustainability School
Free sustainability skills, training and support delivered to thousands of UK companies to help cut carbon.
The Building Safety Forum at the Installershow 2025
With speakers confirmed for 24 June as part of Building Safety Week.
The UK’s largest air pollution campaign.
Future Homes Standard, now includes solar, but what else?
Will the new standard, due to in the Autumn, go far enough in terms of performance ?
BSRIA Briefing: Cleaner Air, Better tomorrow
A look back at issues relating to inside and outside air quality, discussed during the BSRIA briefing in 2023.
Restoring Abbotsford's hothouse
Bringing the writer Walter Scott's garden to life.
Reflections on the spending review with CIAT.
Retired firefighter cycles world to raise Grenfell funds
Leaving on 14 June 2025 Stephen will raise money for youth and schools through the Grenfell Foundation.
Key points for construction at a glance with industry reactions.