How a radical plan to build 40,000 homes on London's existing roofs could help fix its housing crisis

Screen Shot 2017 11 14 at 11.55.44Google Maps / Business InsiderKnight Frank’s ‘Skyward’ software identified 42 Reeves Mews as a potential development space.
  • Property firm Knight Frank has identified potential space on London’s rooftops for up to 40,000 homes, worth £51 billion.
  • Industry figures believe it could alleviate London’s chronic housebuilding shortage.
  • Developers Apex Airspace have started building modular homes on roofs in the capital.

LONDON — Up to 41,000 new homes could be built in central London using space on existing rooftops, according to research from property firm Knight Frank.

The study, which uses “geospatial mapping software,” called Skyward, identified over 28 million square feet of potential residential floor space, with a development value of £51 billion.

London is in the throes of a huge housebuilding crisis, with figures released by the London Mayor’s office suggesting the capital needs to double its housebuilding activity from 29,000 homes a year to 66,000 a year to deal with a growing housing shortage.

One of the biggest problems hampering the pace of housebuilding in London is a lack of space, which could be partially addressed by building upwards.

Currently, planning restrictions make building on top of existing buildings difficult, but the government is considering introducing regulations which make it easier.

The government’s 2017 Housing White Paper, which called for high-density housing in areas like London in locations “where buildings can be extended upwards by using the ‘airspace’ above them.”

Apex Airspace

So how would it work? Business Insider met Val Bagnall, business development director at Apex Housing, at a housing conference in March. Apex’s business model is striking and simple: it builds homes on top of existing ones. Ideally, the roof of the existing building is flat, but pitched roofs aren’t a problem either.

Apex simply removes the pitched roof, installs an extra layer of housing, and puts the roof back on.

Bagnall told Business Insider the firm has itself identified £54 billion of development potential on London’s roofs, both on top of retail spaces and privately owned residential buildings.

“People are still unaware of the value that sits above them,” he said. “We’re trying to unlock the market.”

Apex’s pitch to the freeholder is roughly the same as a conventional development: the firm offers around 25% or 30% of the total sales value of the resulting units.

It is also in talks with Tesco to develop on the flat roofs of the supermarket’s buildings. Bagnall believes Tesco’s London roofs alone could have £400 million of development potential.

Apex has built only built two single units to date, but earlier this year signed a deal to build 28 flats above a building in Southwark, 11 of which will be “affordable.”

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