In 1999 the City of Stockholm arranged a competition on how to use the city’s main square, Sergelstorg. The existing urban space is divided on two levels and the competition was organised to seek solutions to developing the square at ground level only. A team including Ralph Erskine and Richard Rogers was put together. The team put forward a solution where a new narrow building placed on one edge of the square facing to the existing cultural centre building. The two buildings were linked together by a retractable roof that would extend the possibilities to use the space, both in climate around the seasons and in the variety of supporting function.