Room - Donut Shaped with Height Constraint

Example - Donut Shaped Room with Height Constraint

Height Constraint using Keep Objects Outside

Create two Arcs with Crosshairs.

Draw Rectangular Room, ignore self-intersecting warnings while drawing the polygon. Then Edit Polygon Room Vertices to form joined 90 degree Arcs using Snap to Lines and Arcs. 

or

Draw Lines and Arcs then Tools > Convert > Create Room From Selected Primitives.

Notes:

Height Constraint Syntax -  AsMM(Height) > 0.6

Height Constraint - Online DRC does NOT work (bug ?)

Height Constraint - Batch Mode DRC Check works.

Use Shift + Space Bar to Pull Lines to Arcs.