The Olympic Stadium, designed by architects Populous, is a contender for the RIBA Stirling prize. Photo: Mike Walker / Rex

This year’s shortlist for the Stirling Prize is strong, but how will the construction downturn affect this prestigious award in the future, asks Ellis Woodman.

So severe has been the downturn in construction over the past four years that it is soon going to prove a real struggle to find half a dozen buildings worthy of shortlisting for the Stirling Prize, the annual award for Britain’s best new building.

Architecture, however, is a slow business. The six buildings in contention for this year’s prize were all commissioned prior to the downturn. They are among the last fruits of the boom years and, more than a little ironically, comprise a shortlist as strong as any in the Stirling’s 16-year history.

David Chipperfield’s £35 million Hepworth Wakefield – the largest purpose-built art space to have been created outside London in decades – is certainly not the kind of project that is getting commissioned today. It is named after Wakefield-born Barbara Hepworth, whose work features prominently in a collection focused on 20th-century British sculpture.

Sculptural concerns inform the building’s form, too. It comprises a cluster of 10 trapezoidal blocks, which project into a crook of the River Calder like a geological outcrop. This is a challenging building, but the conviction with it has been built and the geometric complexity of the galleries proves hugely seductive.

In Belfast’s Lyric Theatre, the work of O’Donnell and Tuomey Architects, we also find a concern with jagged, rock-like forms, although this time realised in Belfast’s characteristic red brick. The Lyric occupies a hillside site from where it monitors a curve in the River Lagan below. The plot was not large and a pronounced slope cut across it, but the architects have responded to those challenges ingeniously. Their foyer reads as a landscape in miniature, formed of brick-faced plateaus that are set at different levels up the slope and linked by a broad and rangy sandstone stair. This buckles repeatedly as it climbs, presenting at each turn a judiciously framed view before finally delivering us to a cave-like auditorium at the top. It is a powerful spatial sequence – all the more so for being compressed onto a pocket-handkerchief site.

There are two buildings on the list by the Office for Metropolitan Architecture, the firm of Rotterdam’s Rem Koolhaas. They are strong projects but, having visited them, the uninitiated might be left rather baffled by the architect’s reputation for radicalism. At 16 storeys, the new headquarters for Rothschild Bank in the City of London was never going to go unnoticed, but as befits the building’s location at the heart of a conservation area, its design is a model of discretion. This is the antithesis of the wackily shaped skyscraper of Shard and Gherkin fame. The client’s commercial prowess is communicated by more subtle measures, such as the building’s elevation above a travertine-faced porte-cochère which opens up previously concealed views of the churchyard of Wren’s St Stephen Walbrook.

OMA’s other contender is also far from demonstrative – reflecting, in this case, a well-pitched emotional sensitivity. Standing in the grounds of Gartnavel hospital in Glasgow, it is the latest cancer care centre to be built by the charity Maggie’s.

As with other Maggie’s Centres, the building is, in all but its actual function, a house – a reassuringly domestic environment where patients and their families can access advice, information and support. Configured like a ring of wagons, the structure snakes between trees planted around its perimeter and in its central courtyard. Large expanses of floor-to-ceiling glass ensure that their presence is strongly felt inside, too. This is as Californian a building as Glasgow has ever seen.

In the glorious setting of the University of Cambridge’s botanical gardens, Stanton Williams Architects has built the £82 million Sainsbury Laboratory, where 120 botanists devote their days to elucidating the regulatory systems underlying plant development. If the word laboratory brings to mind a hi-tech and clinical architecture, think again: with façades elegantly composed of honey-coloured limestone piers and an interior as meticulously crafted as that of any university library, the Sainsbury leaves no doubt that, for all the technology it houses, it is a building shaped around people.

And finally, there is the most famous building on the list: the Olympic Stadium, designed by architects Populous. This is a building that was conceived as a sustainable alternative to Beijing’s Bird’s Nest, employing a fraction of the steelwork used in that goliath of a structure and designed to be part-dismantled after the games, ensuring that it didn’t suffer the fate of becoming a white elephant. Now it has proved so successful that the hope is to keep it, although what function it might be put to remains unclear.

Selling it to West Ham is one option, although the challenge of transforming it for use as a football stadium is considerable. At present, Chipperfield is the bookies’ favourite to take home the Stirling on Saturday night, but given the strong popular feeling that the stadium has attracted, Populous would certainly be worth a bet.