Out of Thin Air Building above London's rail lines 1 Executive summary Everybody knows that we need more housing. The But this is much more than simply an exercise in issue is where do we put it? London needs 50,000 creating housing, or even retail or office space. It is new homes every year until 2025 just to keep up with also about a sustainable vision of urban improvement housing demand. Yet between April 2016 and March that results in vibrant, connected communities; it 2017 only 6,423 homes (affordable and open market) is about developments that are infused with urban were completed. Making up the shortfall therefore authenticity, where people aspire to live and which demands inventive approaches to development. add value to surrounding areas. Rail Overbuild offers a way forward to address the And like all visions it looks to the future. A vision pressing shortage of housing that exists that achieves not less, but more densification in in London. urban centres by creating pedestrian-orientated communities that will make city living a far more We have identified sufficient land associated with gratifying experience. To advance this vision, we railway infrastructure to yield more than a quarter of discuss how overbuild can be achieved, its benefits a million new homes in London. Put into perspective, and some of the underlying technical issues. that is around five times the annual minimum needed by the capital. Compared to building major infrastructure projects, rail overbuild could be a quicker and less costly How did we arrive at the figure of 250,000 homes way to unlock large housing schemes. However, possible above London's rail lines (p8)? It's a we also recognise and support the need for major conservative figure based on the assumption that of infrastructure growth in the UK, such as HS2 and all land identified, only 10% is actually developed. Crossrail 2, as drivers for housing delivery. Rail This number refers to construction directly above overbuild can complement such schemes. rail lines, but could increase even further if it unlocks and connects to further developments adjacent to Cities are facing a crisis in managing population Contents rail lines or above a station (page 15). growth and housing provision. Associated issues of loneliness, alienation, mobility challenges, skills A previous WSP report focused on general ‘overbuild’ shortages and a lack of social amenities aggravate the involving better land utilisation by creating new situation. Executive Summary 3 residential accommodation above existing public buildings. Here we put the case for rail overbuild and Rail overbuild is a potential way to start addressing Background 4 the societal benefits that can accrue from creating these issues. It can help increase the supply of new residential accommodation by decking over housing, offices, retail, other social infrastructure, Why we should build above rail infrastructure 5 new and existing railway infrastructure, which and even stadiums, as well as connecting previously can include rail/underground tracks and also divided communities. Existing projects show that the How much land might be available for development? 8 stations. This sort of overbuild is now being seen as engineering is possible; we can start to deliver rail Making housing out of thin air a reality 10 increasingly viable and attractive. overbuild now. 12 benefits of rail overbuild 14 The title – Out of Thin Air – alludes to a critical feature: no new land is required. These brownfield WSP project case studies 15 developments can be undertaken where planning controls allow building over the rail environment. 2 3 Before/After How rail overbuild might be implemented near a major rail terminal in Central London Background Our belief in the potential of rail overbuild to unlock Our work can also be seen as complementing housing in densely inhabited cities did not come out the current London Plan – the Mayor’s spatial of thin air. development strategy – which provides a framework for the boroughs and highlights housing, transport, In 2012, Network Rail asked WSP to contribute its economic development and environment. 40 years' global experience of rail overbuild to a The Plan recognises that rail lines can form barriers Why we should build feasibility study on its applicability for twin and four to movement within sites and can be used to knit track scenarios in both flat and cutting situations. the development into the surrounding area. Building We were asked to challenge standards and innovate over railway tracks can provide opportunities to above rail infrastructure throughout. address existing constraints. Housing continues to be one of London’s most Rail overbuild can allow more people to live in The client encouraged our team to examine a In some cases, such as in the example on this page at intractable problems. Even by the government’s own the city; tube and/or rail services will be close very wide range of deck options including arches, Victoria, “the station, the airspace above its tracks admission, our housing market is broken3. by and so using public transport will be a better prefabricated trusses, semi-mechanical swinging and approaches, and nearby sites have significant experience. Indeed, these developments should arrangements, and construction methodologies. potential for mixed use intensification, capitalising Yet despite this, London continues to be a highly have very favourable public transport accessibility The WSP study also considered different overbuild on enhancement to the public transport interchange attractive place to live and work. Since 2000, levels (PTAL). Proximity to stations may also mean scenarios in terms of building type and height. and improvements to accessibility and capacity”2. London’s population has grown by around 95,000 residents choose to forego car ownership. Fewer cars Other factors including fire, acoustics, vibration, According to the Plan, a minimum of 1,000 new every year on average and by more than 100,000 on the streets (less congestion and lower emissions) safety, possessions, and systems’ impacts were also homes can be provided at Victoria. every year since 2008/20094. could prompt residents to walk and cycle more, considered. especially if new developments have cycle storage. We hope this paper goes some way to explaining just Housed far from their workplace, Londoners These factors will contribute to the healthier streets Our approach aligns with Greater London Authority how feasible and fruitful rail over-site developments often face a long, daily commute. This is not only and lifestyles envisaged by the Mayor. (GLA) recommendations, which advise London can be. For building upon existing facilities can not stressful but also creates more overcrowding on boroughs to ‘identify and seek to enable additional only provide much-needed housing but can also an increasingly pressurised and fragile transport As well as contributing to greater public transport development capacity’ to supplement housing regenerate cities and provide benefits to developers, system. use, car-free zones and more walking and cycling, targets. In particular, the GLA recommends the landlords and society as a whole. rail overbuilds can provide a pleasant environment realisation of brownfield housing capacity via Building above railway infrastructure offers a more supporting new homes and jobs, especially as the intensification; town centre renewal and mixed creative use of land. It also fully aligns with the development unlocks growth in the immediate use development (especially of surplus commercial three key themes running through the Mayor’s Draft vicinity. capacity and spare public land, particularly that with Transport Strategy5, which emphasises: good transport accessibility)1. Such a strategy could provide some of the housing Bill Price 1. Healthy streets and healthy people; and healthier environments that London needs. Strategic Growth Director 2. A good public transport experience, and WSP 3. New homes and jobs. 3 Department for Communities and Local Government, Fixing Our Broken Housing Market, February 2017 4 GLA Economics, Economic Evidence Base for London 2016, 1 GLA: The London Plan, Ch 3, London’s People, Policy 3.3 Increasing the Housing Supply 5 Mayor’s Transport Strategy, draft for public consultation, June 2017 4 2 The London Plan March 2016, p373 5 Before/After What building above an Underground station in London might look like CGI of 12-storey building above rail lines in West London Housing deficit data normally have air rights above their real estate which gives them the opportunity, subject to The capital needs 50,000 new homes to be planning policy considerations, to develop above constructed every year till 2025 just to keep up the facility. This prospect may be sold or leased to with projected housing demand. Yet between April other parties. 2016 and March 2017, only 6,423 homes (affordable and open market) were completed6. Making up the Using air rights to create new developments shortfall demands more innovative approaches to above railway assets has many benefits, not least development. of which is that no new land is required. You are literally creating land ‘out of thin air’. So housing Creating more homes in the city centre has over existing railway infrastructure can increase been an ongoing process – since 2001, 90% of the availability of residential accommodation in homes in London have been built within 1km of the capital and help alleviate the current housing a station. In 2013, the former Mayor of London’s shortage. New Draft Housing Strategy recommended that more homes could be delivered by increasing the Our suggested overbuild schemes comprise density of new schemes (densification) and using 12-storey developments that could equally be given infill developments. Part of the current Mayor's over to residential or commercial purposes. These draft strategy7 to increase housing provision is to oversite developments could also form part of identify and bring forward more land for housing, adjacent site developments (ASD) that create new supporting a more intensive use of London’s communities, fuel economic growth and jobs, and available land.