Construction work has begun on the the expansion and renovation of the Bilbao Fine Arts Museum in Spain, which is being designed by British architecture practice Foster + Partners. The new extension is a unique structure that rests respectfully across the existing museum equipping it with 2,300 square-metres of new gallery spaces. The top floor contains a flexible, column-free, exhibition area which can be configured for a large range of displays, with all the service spaces neatly contained within two technical walls. Natural light filters through a panoramic window offering expansive views over the adjacent park, with north lights that can be moderated to suit the displays.