This is an extension of the Museum of Modern Art in Lille, made by the french architect Manuelle Gautrand. The architect's intention was to create a irregular pattern to restrict light levels in the museum. Gautrand uses an uniform silver-grey precast concrete articulated by the wandering pattern of organic perforations.
They used Ductal, an Ultra Performance Fibrous Concrete developed by Lafarge. ( http://www.ductal-lafarge.com/) The concrete pannels are 90mm thick (around 0.35 inches). They are prefabricated and transported to site and hung from a concrete beams and tied to the base slab by plates and insert. In addition, 2000 square meters of thin concrete were cast in site for the blind walls. The architect explains that the prefabrication was ruled out to avoid insightly joints, and the shells were poured on site, using self-compacting concrete to ensure a perfect spread of the mix in the formwork. Mould were made from timber, which could adapt to the different volumes. Moulds for the 30 mm deep inset motifs were made of plywood covered with a thick coat of moulded polyurethane.

http://www.dezeen.com/2010/10/07/lille-metropole-musee-extension-by-manuelle-gautrand/

http://www.manuelle-gautrand.com/projects/modern-art-museum/

http://www.architecturetoday.co.uk/?p=10867