11 DEC 2018


Leading engineers from WSP have provided revised projections for the capital’s housing capacity with cutting-edge technology identifying 14% more land with potential for overbuild. 

Experts, using GIS technology, 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. 

A little more than 12 months ago, WSP produced a report entitled Out of Thin Air which suggested 250,000 new homes could be in built in Greater London and potentially solve the widely known housing crisis by building over open railways.

But after developing the new technology in collaboration with UCL’s Department of Civil, Environmental and Geomatic Engineering, the new research uncovered 14% more land and showed that the London boroughs of Brent, Ealing and Croydon and TfL Zones 2, 3 and 4 provide the most ‘overbuild’ development potential to deliver the 280,000 potential homes.

The latest report - Out of Thin Air – One Year On - 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.

WSP also 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. 

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.

WSP director Bill Price rail believes overbuild is not just about creating new homes but also about creating new, safe, environmentally-friendly and vibrant communities that such developments can offer.

“As an industry we need to focus on radical solutions to overcome the housing crisis in our capital,” he added. “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.”

With housing arguably London’s biggest challenge moving forward, the report has important recommendations for mayor Sadiq Khan who 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.


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