Horizontal Fire Compartment
1. Start by check the Thickness of the structural floor in the project,
otherwise use 300mm thick floors as a guideline.
2. Open a 3D view, turn off all categories except Floors & Generic Models.
3. Create a model-in-place
(Architecture → Component → Model-In-Place),
choose category Generic Model.
Name the new family for instance with Fire_Level 1.
4. Set the workplane to Level 1
5. Choose Extrusion tool and select pick lines in Draw panel.
6. Hover above an exterior line of the floor, press the tab key until all lines are pre-selected and select.
Do the same for all shafts / elevator shafts / staircases.
7. In properties, change Extrusion End / Extrusion Start, Subcategory and turn off in Visilibity/Graphic override that the geometry does not show in Plan view.
Start / End point should be in the middle of the floor,
in this example is the floor 270mm thick, so Start = -136 and End= -135, so it is 1 mm thick.
8. Finish the Extrusion and Finish the Model-In-Place.
9. For the next horizontal compartmentation follow step 3-8.