Finalists have been announced in the New London Architecture (NLA) New Ideas for Housing competition. The contest, run by the city's built environment think-tank, sought ideas to solve London's housing crisis. Proposals included shared housing, communities on the Thames and suburb megacities.

As with many major cities around the world, London's housing provision is under increasing strain. NLA chairman Peter Murray argues that the way the city's housing is currently being delivered isn't working.

"London is only able to build half the number it needs each year," explains Murray. "This competition shows how a bit of creativity, entrepreneurship and new thinking can help to fill that gap."

New Ideas for Housing was an international competition and received more than 200 submissions from 20 countries. Each entry proposed a way to tackle London's housing shortage, with an eventual 10 selected as finalists.

"Some ideas were eye-catchingly radical, such as a floating neighborhood transforming sites on the Thames," says London's deputy mayor for housing, land and property Richard Blakeway. "Others were simple yet brilliant, such as redefining the index of public transport accessibility. Without a doubt, the entries showcase some exciting ways to challenge the traditional approach to house building..."

Below is an overview for each of the shortlisted concepts.

The Urban Darning Project – Patrick J.A. Massey, CZWG

The Urban Darning Project is inspired by the patching or repairing of holes in clothes. It proposes filling in the gaps and spaces in the existing built environment. To do so, it is suggested that each London borough would commission a report to identify suitable sites and how their use could be implemented.

Housing over public assets – Bill Price, WSP|Parsons Brinckerhoff

Price says there is scope for 630,000 new apartments to be built in London above public buildings, such as hospitals, schools and libraries and that this would "comfortably meet the projected 488,000 homes that will be needed in the capital in the next decade." To deliver these apartments, it is suggested that private companies would refurbish or fully rebuild the existing public building with the accommodation added above it. This process would be paid for by then selling or renting out the accommodation.

Supurbia – HTA Design LLP

With its Supurbia concept, HTA suggests "intensifying London’s suburbs." The proposed approach is said to be twofold, with local main streets and parades redeveloped to become mixed-use facilities with more housing and amenity provision and owner-occupiers of semi-detached homes allowed to develop their land to provide yet more housing. HTA says this would enable homeowners to release equity in their land, while reducing the reliance on mainstream developers to build housing.

Intimate Infrastructures – Natasha Reid Design

Natasha Reid Design's idea is to provide purpose-built shared housing. The firm says this would both provide accommodation for private renters and lessen the impact of local communities that are vulnerable to displacement. Mass-produced modular housing would ensure the concept could be delivered quickly and cost effectively.

Buoyant Starts – Floating Homes Ltd with Baca Architects

Floating Homes and Baca Architects look to the waterways for their solution. They suggest that 7,500 prefabricated floating starter homes could be accommodated along the 50 mi (80 km) of rivers and canals in Greater London and in the 150 ha (371 ac) of developable waterspace in the city’s docks, marinas, and basins with minimal disruption to existing communities.

Investing in London’s Future by Learning from its Past – David Kroll

Kroll proposes revisiting the leasehold system of development from London's past. Suitable public land would be made available for building on, but would remain publicly owned. Only the planning and construction of the buildings would be in the hands of private developers, meaning new accommodation could be sold or rented at reduced prices, with a ground rent for the public land able to be strategically set.

Mega Planning, Beyond 2050: MegaPlan for a MegaCity – GL Hearn part of Capita Ltd

GL Hearn posits that, by 2050, London will have become Europe's first megacity (a city with a population of over 10 million). It says that the city's shortfall in housing by this point could be served by freeing up 4 percent of its green belt "Edge Land" within the M25 ring road. Although controversial, the firm suggests a strategic green belt review could be carried out to select appropriate places for reclassification.

ATAL Opportunity Areas – Brendan Cuddihy, Arup, and Rupesh Varsani, Craigewan

This collaborative concept is a proposed alternative to that in the London Plan, which favors the construction of new housing in areas that have good access to public transport. The suggested Active Transport Accessibility Level (ATAL) would encourage home building in areas that have less access to public transport, coupled with the construction of infrastructure to support active forms of travel such as walking and cycling. It is suggested that achieving a high ATAL would allow for a doubling of development density in over half of London.

Making more with less: unlocking leftover land for generation rent – Pitman Tozer, LB Enfield and Naked House

This scheme would see the development of underused council-owned sites for affordable housing. Not-for-profit housing provider Naked House would act as the developer for the project, taking on the associated risk and managing the process. It is thought that as many as 110,000 affordable customizable homes could be delivered in this way by 2025.

Wood Blocks – dRMM Architects

Wood Blocks are "ready to camp in" housing structures that can be partitioned and fitted-out however the resident wishes. They are said to be weatherproof, insulated and acoustically-insulated, with the potential of being able to reduce the cost of building new homes by up to 40 per cent.

The New Ideas for Housing competition was launched in June. The shortlisted ideas will now be presented to the Greater London Authority who will study their feasibility. An exhibition showing 100 of the competition entries will run at the NLA Gallery in London from Oct. 15 to Dec. 17.

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