Looking for space for homes in the capital? Build over rail lines

A new survey of housebuilders published last week by construction consulting and design agency McBains is depressing reading for Londoners looking to get a foot on the housing ladder.

Although two thirds of housebuilders in London reported that they had built more homes over the last 12 months, those that stated a decrease cited a shortage of available or appropriate land as the main reason for a fall in their rate of housebuilding.

The shortage of housing compared to demand is the biggest factor driving the huge price increases and continued unaffordability that has become a feature of the London market.

In the last 20 years, there has been a 40 per cent rise in the number of jobs in the capital, but only a 15 per cent increase in the number of homes.

London mayor Sadiq Khan has set a target of building 66,000 new homes a year. This still falls short of the number required, and current construction rates are depressingly less than half of that target.

As the McBains survey shows, one major problem is the lack of available space in London for new homes. We can’t magic up more land, so that means we need to be more creative with the space that exists.

Significant inroads are starting to be made by utilising property owned by Transport for London (TfL). And there is potential in even the most unexpected places.

It might surprise you to learn that TfL is one of London’s biggest landowners, owning 5,700 acres across the city – and in some of the capital’s best-connected areas.

Work is already underway to turn some of that land into residential development. In the last financial year, TfL made 22 sites available for 3,850 homes. It plans to release enough land in 2019 for up to 4,000 homes, and is working towards 15,000 homes by 2021. Crucially, many will have an affordable housing element.

Examples include the redevelopment of Morden station, earmarked to deliver 2,000 homes; Kidbrooke, where an application has been submitted for 619 homes (50 per cent of which are affordable); and Blackhorse Road, where a car park will be transformed into 350 homes.

But building on TfL property could be just the tip of the iceberg. We should be looking at the space above London’s wider rail network, too.

It has been estimated that available space above the capital’s Overground and Tube tracks could free up almost 2,500 hectares of land and deliver as many as 280,000 new homes. Brent, Ealing, Croydon and TfL Zones 2, 3 and 4 provide the most “overbuild” development potential, while in central London, Wandsworth, Newham and Hammersmith & Fulham also rank highly.

It is true that building close to rail or Tube lines isn’t straightforward. For example, one of the sites that we worked on – White Lion House at Centre Point – was developed above the tunnels for Crossrail while the new railway was under construction.

That meant we had to think smart. This nine-storey residential block providing affordable homes in central London was designed with a unique structure that put all the weight on its northern half, where deep foundations could be placed – effectively allowing the southern half to cantilever above the tunnels.

This innovative approach to structural engineering allowed significant additional square feet of living space throughout the building. It demonstrates the potential in London of making the most of every possible available space.

With space at such a high premium, maximising even small amounts on each site could mean hundreds of additional homes overall.

London has already made start in recognising the potential in terms of building close to railway and Tube lines. But if we’re even more ambitious, there could finally be a light at the end of the tunnel for the capital’s housing crisis.