Engineering firm WSP has calculated that utilising the space above railway tracks in London, could provide enough space to built 280,000 residential units.

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 railway lines.

The 2,470 hectares of land which could be utilised, was found by through a collaboration between WSP and the University College London’s Department of Civil Environmental and Geomatic Engineering. This is a new methodology using GIS technology, which allowed WSP to uncover 14% more land with the 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 proposals.

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 a minimum of 100 metres in length.

Research from the report identified the area of land associated with all exposed railway lines in London’s fare zones 1-6. If a conservative 10% of this total was delivered, it could provide 280,000 new homes for London. This is based on the assumption that the proposed buildings would be 12 storeys high with homes of 100 metres squared.

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 are also ranked highly.

Bill Price, Director of WSP said: “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.

Price adds: “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.

“They achieve the densification that London’s local authorities can use as economic development tools to provide growth, connectivity and jobs in the community.”

19 December 2018