Unconditioned space is the area inside a building shell with no attempt at control of temperature or humidity. Unconditioned spaces should be included in the load calculations for the model's accuracy. To model unconditioned spaces, select the 'Void' template within the drawing.tool or assign via Room Templates.
Selecting the 'Void' template models the room with no internal loads, and a wide temperature band, resulting in the behavior of a completely empty room. The 'Void' rooms do not need to be assigned to a zone. When running the simulation, the unconditioned rooms will be auto-assigned to a default system (Ideal Air Loads) which will remove these rooms from the system sizing of occupied zones.