Somerset House hosts an exhibition from the Royal Institute for British Architects (RIBA) that showcases ambitious and innovative designs from leading designers as part of its Forgotten Spaces competition.

In partnership with the Landscape Institute, the Mayor of London and the Royal Town Planning Institute, RIBA invited architects, artists, designers and planners to submit proposals to reimagine abandoned or underutilised sites across Greater London. This resulted in 147 entries, whittled down to the 26 finalists displayed in the exhibition.

Curated by RIBA's Antonia Faust, Somerset House has made use of its own forgotten space. Situated underneath Somerset House's famous fountains and in its surrounding disused coal stores, visitors are given a peek into the underbelly and some of the more macabre aspects of one of London's most famous houses. The numerous 17th-century tombstones set into the walls of this crypt-like space offer a fascinating insight into the history of Somerset House and the surrounding area.

In between the tombstones, the finalists' submissions are displayed on just two A1 boards with the occasional model or installation. With a restricted space to exhibit in, the curator and designers have done well to convey their ideas. For the designers, there were no other restrictions to their imagination, and as a result proposals ranged not only in scale and cost but also from practical, innovative design solutions to more quirky and peculiar ideas.

First prize of £5,000 was awarded to 4orm for "Fleeting Memories", an ambitious and costly project that aims to replicate a similar scheme from South Korea in exposing one of London's lost rivers, the River Fleet, at the expense of one of London's major highways. The second prize of £2,000 was awarded to "Aquadocks" by Pink Studio, who propose making use of space underneath the Silvertown flyover with the rather unrealistic ambition of developing the site into a swimming pool and spa. Third place of £1,000 went to"Silvertown Brewery" by Chris Allen, Marcus Andren and Michael Gyifor who propose to redevelop the same site as Pink Studio, but with the more practical ambition of a microbrewery and bowling venue.

Despite the first and second prizes being awarded to those submissions with the most elaborate illustrations, it is worth examining the design solutions from other contestants, such as the "Bikebox" by Sam Rose and Hoi Kei Lo – an achievable and affordable solution to encourage and support London's increasing number of cyclists. They propose to take advantage of an existing scheme by BT to adopt telephone boxes and refit them with a simple bicycle repair kit station.

Another exciting and feasible proposal comes from architect father-and-son duo, Peter and Ian Wale. Tackling one of London's less-than-savoury sites, a decommissioned sewage treatment site in Kingston-Upon-Thames, their submission is titled "Urban Agri-Aqua Culture". Bearing in mind the limitations of what can be built on contaminated land, they propose to reinvigorate the site with innovative urban farming techniques. Utilising the former sewage works' tanks to farm fish, they aim to integrate waste products from the fish into a wider agriculture system. Urban Agri-Aqua Culture also aims to make the site useable for different groups in the community with a visitor centre and shop. Due to increased food security risks and an increasingly obese society, Urban Agri-Aqua Culture's environmental and community credentials no doubt would see it gain backing from the likes of Hugh Fearnley-Whittingstall and Jamie Oliver.

With a choice of 26 designs to view and judge, Forgotten Spaces includes what are arguably the most important social issues we face today. However, the exhibition is not all serious and thought-provoking design. John Thompson's design for The Centre of Forgotten Beer, like the third place winners, works with the trend of microbreweries establishing themselves in the capital. "Canopy" by Studio McLeod proposes building ladders and platforms into London's trees to release your inner child for a spot of escapism – a design many would love to see fulfilled; however, the fun police will probably see to it that it does not go any further than the drawing board due to health and safety concerns.

Along with other quirky and serious designs, Forgotten Spaces provides an engaging and educational experience that can be enjoyed by all. 

RIBA Forgotten Spaces 2013, at Somerset HouseSarah McSorley's review of RIBA Forgotten Spaces at Somerset House.5