Following its design of the UK's "first amphibious house", Baca Architects has unveiled a floating house concept that could be deployed across London's waterways as a solution to the lack of new homes in the capital (+ slideshow).

The London firm worked with Floating Homes Ltd to develop the Buoyant Starts floating housing concept for a housing competition hosted by think-tank New London Architecture (NLA). It is among the 100 longlisted entries to the competition, which drew over 200 submissions from around the world.

The project aims to install prefabricated floating housing on disused space along the 50 miles of rivers and canals in Greater London, as well as the 150 hectares of additional "bluefield" space in its docklands, marinas and basins.

The scheme could deliver up to 7,500 affordable homes – costed at £150,000 for a two-bed unit – in the centre of the capital.

"Exploration into taller buildings, higher density modules, less conventional space planning and shared spaces rarely complies with typical national, GLA (Greater London Authority) and local policy but may provide good 21st-century solutions to ease housing pressure," said the firm.

"Buoyant Starts aims to address the housing crisis in Greater London by providing high-quality, prefabricated floating homes at an affordable price on the un-used water space of the capital."

A second concept called Innovation Licence, which has also been long-listed in the NLA competition, aims to provide one-off building permits for projects that would usually be rejected under London's current planning policy.

The architects suggest that the projects, which would be required to have an environmental remit, could make use of floodplains around London's waterways.

"The Innovation Licence is a radical new idea to deliver more housing, more quickly, and with higher densities," said the architects.

"An alternative to the traditional planning system, licences would be granted for innovative buildings and designs to be carried out on challenging sites, such as floodplains or deprived areas."

Both concepts build on the studio's Amphibious House project, which was designed to help resolve the issue of the River Thames' flood waters.

Earlier this year London architect Carl Turner released plans for a prefabricated floating house on an open-source architecture website. "Part-house and part-boat", it too is designed to deal with flood-prone sites.

Other housing designs aimed at solving London's housing shortage include the Y:Cube prefabricated development by Rogers Stirk Harbour + Partners, which costs £30,000 per unit.

Imagery is courtesy Baca Architects.