Foster + Partners' Newest Energy-Efficient Structure for Amsterdam [S2]

Construction just finished on this 24-story building designed by Foster + Partners for Vivaldi Park area in Amsterdam.  It's quite the efficient structure -- exceeding Dutch environmental regulations by 10%, and features flexible floor plates that are perfect for big name tenants such as Ernst & Young.  The design calls for an ecological pond, fully glazed windows on sun-exposed facades, and the retention of 65% of rainwater.  In addition to its energy efficient elements, probably one of the more interesting aspects of the structure, and one that has grown on me, is Foster + Partners' signature use of the aluminum-clad, steel diagrid structure.  Any thoughts relating to the diagrid pattern on the building exterior?

Via Foster + Partners.

[S2] = Skyscraper Sunday, a weekly article on green skyscrapers.