Some 280,000 homes could be built in the space above train, overground and tube lines, according to a new report by engineering firm WSP.
In response to strong demand for housing in the capital, WSP worked with University College London’s (UCL) Department of Civil, Environmental and Geomatic Engineering to develop a new methodology using GIS technology to work out how much rail land best suited for residential development is available.
The report, Out of Thin Air – One Year On, builds on a previous WSP report called Out of Thin Air, which estimated 250,000 homes could be found by building apartments above rail.
Using the new methodology, WSP has now revised that figure updates to 280,000 – a rise of about 14%.
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.
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, WSP said.
The new research identified the London boroughs of Brent, Ealing and Croydon and TfL Zones 2, 3 and 4 as having the most ‘overbuild’ development potential. In central London, Wandsworth, Newham and Hammersmith & Fulham also rank highly.
WSP also looked at how the methodology could be applied internationally. By applying a simplified analysis of available land in cities such as Melbourne, Sydney and Vancouver, it identified a potential 77,400 homes, 29,160 and 46,033 respectively.
Bill Price, WSP director 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.”
He added: “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.”
Mayor of London has identified a need for 66,000 new homes a year in the capital in order to meet demand but WSP pointed to recent NHBC data showing that 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.