Modeling: Walls, Floors, Roofs, and Ceilings
Modeling questions test whether you understand hosted vs. non-hosted elements and sketch-based geometry. Walls come in basic, stacked, curtain, and curtain-system varieties; each has a location line (wall centerline, core face, finish face) that determines where the wall sits relative to your pick points. Getting the location line wrong is the classic trap.
Floors, roofs, and ceilings are sketch-based. Floors are usually drawn by picking walls; roofs can be by footprint, by extrusion, or by face. Ceilings are almost always created in a reflected ceiling plan and are hosted by a level, not a room. Know that a sloped floor uses a slope arrow, and a sloped roof can use a slope-defining edge.
Traps: a wall's top constraint and base constraint are instance parameters, but its function and structure are type parameters. Join geometry and cut geometry are different operations; join cleans up intersections, cut removes material. Attach top/base makes a wall follow a roof or floor. Room bounding must be enabled on a linked model or a floor slab for rooms to compute correctly. A curtain wall is not a wall with glass; it is a distinct family type with mullions and panels.
Rule of thumb: any element created by drawing a closed loop in a sketch mode is sketch-based, and its sketch is editable later by selecting the element and choosing Edit Boundary.
Worked example: a wall does not reach the roof. Check the top constraint level and whether Attach Top/Base was applied; if the roof is at a different elevation than the constraint, the wall will stop short.