City Hall in London, the brutalist Derby Assembly Rooms and Swindon's Oasis Leisure Centre are among the UK's top 10 buildings under threat according to architectural campaigning charity Twentieth Century Society.

Revealed today by the Twentieth Century Society (C20 Society), the Top 10 Buildings at Risk List for 2021 highlights structures that the charity believes are in danger of either substantial alteration or demolition.

Other buildings at risk include the Bull Yard shopping precinct in Birmingham, the listed Halls of Residence at the University of Hull and the Cressingham Gardens' housing estate in London.

The list, which is released every two years aims to illuminate how numerous buildings of various architectural styles are currently under threat in the UK.

"It helps the architectural campaigning charity to demonstrate how severe the threat is to some of the very best examples of the architecture of our period, and ensures that some of its longest and most intractable cases do not fade from view," C20 Society explained.

City Hall among buildings at risk

One of the most significant buildings on the list is London's City Hall, a glass-clad government building on the south bank of the River Thames that Foster + Partners designed as a slanting ovoid.

City Hall has been the home of the Greater London Authority since it opened in 2002, but the C20 Society is concerned for its future as the governing body is set to relocate.

In a bid to ensure suitable reuse of the building by the new occupant, the C20 Society is calling for it to be listed.

However, an application for this was rebuffed by Historic England as it is not considered to be immediately at risk, according to the charity.

Oasis Leisure Centre in Swindon is on the list following the reveal of refurbishment plans involving the demolition of its centrepiece – a perspex-glazed roof dome.

The charity argues that the building, which is best known for informing the name of the band Oasis, needs protecting as it is one of few surviving leisure facilities built in the 1960s to 1980s to be enjoyed by families, rather than for training or competitions.

Brutalist buildings under threat

The brutalist Derby Assembly Rooms made the top 10 list after the local council revealed its plans to demolish the concrete edifice in Derbyshire without plans for a replacement.

Derby City Council's announcement has sparked uproar from architects across the UK, and its proposal for a pop-up market to take the Assembly Rooms' place has been described by C20 Society trustee Otto Saumarez Smith as a "grotesque failure of imagination".

Another brutalist building on the list is the Swansea Civic Centre in Wales, which the local council is planning to replace as part of the regeneration of the city centre and waterfront.

Like several other structures in the Top 10 Buildings at Risk List for 2021, the C20 Society has submitted an application to have it listed at Grade II.

Only one building under threat currently listed

The Bull Yard shopping precinct in Coventry could suffer a similar fate, with post-war buildings at risk of being lost as part of a 60,000-square-metre redevelopment scheme planned by the local council.

The shopping precinct ranks number one in the Buildings at Risk List because Coventry is shortly due to be named as the UK City of Culture, which the society believes is being ignored as "a brilliant opportunity for the council to showcase its post-war buildings".

The only structure in the top 10 that is already Grade II*-listed is The Lawns, a hall of residence at the University of Hull, built by Gillespie, Kidd & Coia in the 1960s.

Now up for sale and earmarked as housing, the C20 Society has spotlighted the building to help ensure its future owner adopts "a conservation-led scheme".

Two buildings on 2019 list demolished

Other buildings on the list include the Former London Electricity Board HQ and the Cressingham Gardens post-war social housing estate, both of which are facing demolition in London.

The final two are the Halifax swimming pool and its murals and Shirehall, Shropshire Council's modernist headquarters.

Structures on the C20 Society's Buildings at Risk List for 2019 included two buildings that have been demolished. These are the Fawley Power Station in Hampshire and Walton Court, the former home of Birds Eye in Walton Surrey.

While the remaining eight buildings are still in place, the charity has said that "no positive solutions have yet been found" for them.

Main image is by Garry Knight.