In Vienna, a dazzling penthouse by Delugan Meissl has boldly inserted itself between traditional rooftops of the city’s Wieden district like a recently landed alien intruder. The engineering of House Ray 1’s load-bearing structure was extremely complex. Since the house had to be built on top of an old building, the architects opted for lightweight steel skeleton construction. The living/dining area has sliding glass walls that open to the back terrace and pool.  Photo 4 of 16 in The Penthouse Has Landed