Possible constant values to define the tilt of a surface.
For example, for a construction that is a floor, use
Buildings.Types.Tilt.Floor
.
Note that a ceiling has a tilt of 0 , and also the solar collector models in Buildings.Fluid.SolarCollectors require a tilt of 0 if they are facing straight upwards. This is correct because the solar irradiation on a ceiling construction is on the other-side surface, which faces upwards toward the sky. Hence, a construction is considered a ceiling from the view point of a person standing inside a room.