thick sturdy walls separating the rooms, contain storage closets. http://www.dezeen.com/2013/01/28/house-in-alcobaca-by-aires-mateus/?utm_medium=email&utm_campaign=Dezeen+Mail+137&utm_content=Dezeen+Mail+137+CID_be1eca27134b3e6f75757f4a197bd5f0&utm_source=Dezeen%20Mail&utm_term=Read%20the%20story%20and%20comments White Rooms in Portugal, J9;)