Scenario 4:
Green "Swap"

The Policy

  • To allocate development in areas nearest to demand in the City of Cambridge without changing the existing City environment.

  • No additional buildings beyond existing planning permissions except within designated areas of the Green Belt. Developers to provide new public green areas outside the Green Belt to replace those used.

  • Some new development allowed in market towns of Ely, Huntingdon, St Ives, St Neots.

  • Replacement or renewal of buildings allowed within the City and South Cambridgeshire (e.g., conversion of houses into flats, or warehousing into offices, etc).

  • Transport to remain as it is now (e.g., no increase in road capacity or public transport).

This policy involves significant increases of households in the Green Belt areas of the City and South Cambridgeshire, with smaller increases in East Cambridgeshire and Huntingdonshire.

Employment continues to grow in the City, despite restrictions due to existing permissions for development, substitution of extensive space users by intensive space users (e.g., high-tech business, private and public services, for extensive space) and the development of areas within the Green Belt.. Lesser increases in South Cambridgeshire and beyond.

The Results

  • Dwelling costs increase, but less than in the other options (except Densification), within the City and South Cambridgeshire

  • Less displacement of middle and lower socio-economic groups in South Cambridgeshire by wealthy managerial and professional groups

  • Commercial floorspace costs increase fairly evenly across the areas.

  • Traditional jobs along with new high-tech and private service employment will grow in the City and its fringe.

  • Increased supply of houses near jobs reduces need for more long distance commuting.

The cost of living within South Cambridgeshire (fringes of the City) would increase less than other areas, due to lower increases in house prices and rentals, costs of goods, services and transport.

The cost of production would increase in the region, and at manageable rates due to stable labour costs and floorspace rentals.

Transport implications

  • The close connection between jobs and households means that travel distances will not increase as much as in other options.

  • A higher proportion of trips are made by walking, cycling or bus

  • The sheer number of extra people living on the fringes would increase the number of vehicles circulating on the City’s roads.

  • Traffic delays set to quadruple during the period up to 2016, thus increasing congestion substantially.

  • Emissions and thus pollution increase.

  • Would necessitate radical measures in and around the City to arrest growing traffic congestion.



  • Economic efficiency would be maintained, facilitating the competitiveness of the region.

  • Export-oriented firms such as those in the high-tech sector would find it easier to compete with the rest of the world, facing an increase of about 1.5% per year in production costs (between 2001 and 2016) which could be absorbed by efficiency gains.


  • In South Cambridgeshire the existing social mix (with a preponderance of higher income groups) would be largely stable, because of the greater housing supply.

  • The City of Cambridge would become less segregated due to more affordable housing for lower income groups.


  • Good protection of the buildings and open space within the City.

  • Reduction of Green Belt amenity but compensated by new public spaces further afield.

  • Protection of the environment outside the Green Belt.

  • Net increase in public green facilities.

  • Substantial increases in emissions and pollution in the City due to the concentration of population, employment and traffic.



©Cambridge Futures & METAPHORM - 3D model based on Ordnance Survey © CCC and Crown Copyright. All rights reserved.

The animation above illustrates an area where Green Swap could be implemented. The area is Cambridge Airport, where operations could be transferred to a nearby disused airfield, thus releasing valuable land for development. Newmarket Road runs across the bottom of the picture. The development illustrated is mixed use, incorporating a retail outlet, a boulevard with high density housing and commercial premises. At the top of the boulevard, public services such as schools, health clinics and libraries are grouped around a square.

Adding an extension to the city in this way would be compensated for by adding to the Green Belt further away from Cambridge.

To Option 5 analysis