Utility staircases
Stairs

As the dimensions of the human body (less than 2 m high and around 0.50 m wide) are statistically defined, so are those of the passageways, so staircase dimensions vary little in order of magnitude. In apartment buildings, it is always assumed that the width of the staircase is determined by the passage of the coffin, and that the staircase will turn if the flight of straight stairs is at least 1.10 m wide. A core staircase would require 1.20 m or 1.30 m: these are often too small. The elegant, space-saving solution is an open spiral staircase with 1.00 m rise and 50 to 60 cm clearance (figure 17 ). The radiating steps are still 8 cm wide and rise 2.72 m from...