Brief definition
In an attic with sloping ceilings, only parts of rooms count as living or usable area where specific height and geometry conditions are met. The slope itself must be distinguished precisely from the usable area below.
Practical relevance
Incorrect manual take-off in attics is common. Clean geometric determination from drawings reduces disputes in living-area certificates and early design.
Archible relevance
From 2D sections and floor plans, Archible extracts room geometry deterministically. Professional application of WoFlV allowance and deduction rules remains the planner’s responsibility — Archible supplies the verifiable geometric basis.