Outdoor and Small Patio, Porch, Deck The designer added a 500-square-foot third floor—hidden from the street—with a small, bluestone roof deck, to create a master suite. The roofline was reoriented due south and covered in a combination of solar thermal panels by Stielbel Eltron (to heat the domestic hot water) and Unirac SolarMount SunFrame with 190w photovoltaic panels (for electricity).  Private Rooftop Sanctuaries  by Zachary Edelson from A Sustainable Brownstone Transformation in Brooklyn