It's the detail that counts. Look around the room you're in now, and observe all the places it deviates from four blocks for walls and two planes for floor and ceiling. Look for: wainscotting, door frames, window frames, window sills, cornices, recesses, flat arches. Most rooms are not straight boxes. Incidentally, I reckon rooms are one of Bryce's strong areas because of the useful tools it provides for rotating and positioning things in a precise way.