The interfloor overlap is done with beams and reinforced concrete slabs, the roof insulation is 200/205mm. The recommended height of the supporting walls and partitions on the attic floor is from 0 to 1,7m. Architecture can be simple and complex, usually a  second light" is used and panoramic windows, skylights on the roof are often designed. The price form one sq.m. is lower than for a standard one-story house, due to the common foundation for both floors and the roof, with a smaller area.