This is project by Foster + Partners working with Co-architects Adamson Associates in New York, USA, 2000-2006 - see: http://www.fosterandpartners.com/Projects/1124/Default.aspx
Here the scheme is illustrated and described in detail, with a summarized introduction:
'Hearst Tower’s distinctive facetted silhouette rises dramatically above Joseph Urban’s existing six-storey Art Deco building, its main spatial event a vast internal plaza, occupying the entire shell of the historic base. Designed to consume significantly less energy than a conventional New York office building, it is a model of sustainable office design.'
It shows yet another approach to keeping of old facades.