WSP found that space above train, overground and tube lines could result in an additional 2,470 hectares of land available for residential buildings across London, the equivalent of 280,000 homes

Housing continues to be one of London’s biggest problems. London’s Mayor Sadiq Khan recently suggested that the rate of new residential construction in the capital needed to rise to 66,000 homes a year to meet housing demand. Yet, according to recent data by the National House-Building Council only 2,917 homes were planned for construction in the three months to June 2018 which is the lowest total for that quarter since 2009.

Out of Thin Air – One Year On follows a previous WSP report, Out of Thin Air, which estimated that 250,000 new homes in London could be found by building apartments above rail.

WSP, a member of West London Business, has now developed – in collaboration with UCL’s Department of Civil, Environmental and Geomatic Engineering – a new methodology using GIS technology to provide a more accurate picture of available rail land best suited for development. With this new methodology WSP was able to uncover 14% more land with potential for overbuild than estimated previously.

WSP used a set of socio-economic and socio-environmental criteria such as population density, accessibility to public transport and proximity to local authority opportunity areas among others to mirror factors that play a part in decision-making on development projects.

The team also considered constraints that can arise when looking at a potential site for development, including the length of tracks and the size of the site which needs to be 100m minimum length.

Key findings

Research from the report identified the area of land associated with all exposed rail tracks in London’s fare Zones 1-6. If a conservative 10% of this total was delivered it would provide 280,000 new homes, assuming that buildings would be 12 storeys high with homes of 100m2.

The new research indicates that the London boroughs of Brent, Ealing and Croydon and TfL Zones 2, 3 and 4 provide the most ‘overbuild’ development potential. In Central London, Wandsworth, Newham and Hammersmith & Fulham also rank highly.

WSP took the study a step further and looked at how this methodology could be applied internationally. By applying a simplified analysis of available land in cities such as Melbourne, Sydney and Vancouver, WSP identified a potential 77,400 homes, 29,160 and 46,033 respectively. 

Beyond rail overbuild

Bill Price, WSP Director comments: “As an industry we need to focus on radical solutions to overcome the housing crisis in our capital. Out of Thin Air – One Year On brings us another step closer to unlocking the extraordinary potential rail overbuild can provide, not just for London but in cities across the world.”

Since the launch of the report one year ago, WSP has received considerable support and interest from public and private sectors alike.

But “rail overbuild is not just about creating new homes, it’s also about creating new, safe, environmentally-friendly and vibrant communities that such developments can offer,” adds Bill Price. “They achieve the densification that London’s local authorities can use as economic development tools to provide growth, connectivity and jobs in the community.” 

Map of London can be downloaded here

Report can be downloaded here