Foster and Partners has been picked to develop Seattle's Civic Square - the final jigsaw piece in a 10-year regeneration of the US city's south downtown area.
The design will boast a 120m-tall tower, described as a 'model of sustainable development', which will be surrounded by a large public plaza. There are also plans to build a new light-rail link under the site to enhance access.
Rivulets, fountains and a cascading water feature are proposed as an eye-grabbing entrance to the square. Storm-water-management measures will also be integrated into the $300 million (£150 million) scheme, which has been designed in collaboration with locally based practice GGLO.
An amphitheatre will 'embed' the square into the city, forming a visual link between City Hall on Fourth Avenue and the new People's Pavilion opposite.
Commenting on the project, Foster said: 'Our scheme will combine culture, commerce and community, providing a new civic pace for Seattle. It will create a strong sense of place and a new urban destination for the city that is sensitive to the civic centre masterplan.
He added: 'Our ambition is to create a lasting legacy that will not only lift the fortunes of the area but, crucially, will establish a benchmark for sustainable architecture for future generations.'
The project is expected to complete by 2010.Meanwhile, Foster and Partners' financial future has continued to attract press speculation. Reports in the last 24 hours have claimed that the private equity group 3i is one of three or four bidders hoping to buy into the UK practice. It is understood a final decision will be announced in the next few weeks.by Clive Walker