The London-based firm is one of eight practices, including Dutch star West 8, chosen to draw up plans for the 35ha site on the outskirts of Hamburg.
Assael director Russell Pedley said: 'We are up against some stiff competition, including some well-known European urban design practices, but the team here are really enjoying working on such a large international masterplanning project and I'm confident that our enthusiasm will help us deliver a well thought through and appropriate solution for the city of Hamburg.'
The other practices in the running are:
Arkkitehtitoimisto Brunow and Maunula (Helsinki);
Petersen Pörksen Partner (Lübeck);
Bernhard Winking (Hamburg);
Astoc Architects & Planners (Köln);
Baufrösche Kassel (Kassel); and
Heiko Schellenberg (Dresden).
Four finalists are expected to be announced in January and an exhibition showcasing all the submissions will be held in March.