News: London studio Weston Williamson has won a competition to design a new athletics stadium for Brasilia with a concept for a shape-shifting structure that opens like a flower in response to wind direction and sunlight.

The competition called for ideas for a 70,000-seat athletics venue and Weston Williamson's winning response features a circular building with a skeletal structure modelled on the wings of a bird in flight.

A series of feather-like sections would make up the animated exterior. Each would be able to shift itself independently, adapting to changing weather and lighting but also creating a spectacle during ceremonial occasions.

"The exterior form of the new athletics stadium reflects the utopian spirit of the Brasilia plan by incorporating a geometry that is ever-changing," said the studio. "The stadium, therefore, has no fixed identity, but alters in relation to the condition of its surroundings."

The base of the stadium would be elevated on a wooden plinth and surrounded by pools of water and trees, using passive cooling to moderate the interior temperature.

The competition, which was organised in connection with the Rio 2016 Olympic Games, was intended to be "design constraints free", allowing applicants to "be creative and test the boundaries of what is possible". A $12,000 prize is awarded to the winner.

Other sports venues in Brazil include the National Shooting Centre and the renovated 1960s Mineirão Stadium in Belo Horizonte. See more architecture in Brazil »

Here are a few words from Weston Williamson:

Weston Williamson + Partners Wins First Prize

Weston Williamson + Partners has won 1st prize in the Brasilia Athletics Stadium Competition run in connection with the upcoming Olympics.

The exterior form of the new Athletics Stadium reflects the utopian spirit of the Brasilia plan by incorporating a geometry that is ever-changing. The stadium, therefore, has no fixed identity, but alters in relation to the condition of its surroundings.

The stadium references the iconographic plan for Brasilia, that represents a bird in flight, by incorporating massive feather like structures that envelop the interior. These fine structural elements shift in relation to wind direction and sunlight, meaning that the form is constantly in flux. The movable envelope also acts ceremoniously, reaching upwards to the sky when an event is about to unfold, adding another layer of visual spectacle to the games.

The stadium is situated on a wooden plinth surrounded by water pools and dense greenery which helps to cool the site in the intense heat. A network of shaded facilities is situated beneath this plinth, all lit with top light from perforations within the timber structure above.

The design proposes a fluid icon, suited to an environment that is being continually redefined.