Julie Torres Moskovitz, who designed New York’s first certified Passive House, recently finished her first book, The Greenest Home (Princeton Architectural Press), about the first wave of ultragreen homes in the United States (following the 40,000 already constructed in Europe). The title hits shelves in May 2013. Here, a custom stainless steel stair with treads of perforated steel replaces the old wood staircase in the rehabbed Park Slope brownstone.