Making a floor

Although it is not obvious from the plan views, for the 3D and sectional views of the building it is necessary to create proper floor objects for each of the levels. The procedure is straightforward.

Draw a polygon defining the floor footprint (polygon method)

You can do this in a number of ways. One way is to choose the Polygon tool and click consecutively on the inside corners of all the exterior walls…

Draw a polygon defining the floor footprint (rectangles method)

A second way is to create the polygon as a series of overlapping rectangles (particularly useful when the footprint is not just a rectangle itself), then Modify > Add Surface them together.
NOTE: The rectangles here were given a fill for illustration.

Draw a polygon defining the floor footprint (exterior walls method)

The third – and probably the easiest and certainly the most reliable method – is to ask VectorWorks to do it for you, based on the exterior walls. For this purpose, you would use Custom Selection… to choose all (and only) the exterior walls, by virtue of their Wall Style, for example… –

Create Polygons from Walls

Whichever method you use to select the exterior walls, once it's done, choose AEC > Create Polys from Walls…

Choose Net Area (Room) Polys

A dialog comes up asking whether to create the polygon based on the outside faces of the walls ("Gross Area Polys"), or their inside faces ("Net Area (Room) Polys"). Choose the latter.
NOTE: At the basement level and anywhere else where the floor slab is a supporting pad for the walls above, you should choose Gross Area Polys, for the floor to extend to the outside faces of the walls.

Floor… it

With the polygon created and still selected, choose AEC > Create Floor…

Give the floor slab its thickness parameters

The Create Floor dialog asks for two things (albeit in reverse order):
- the thickness of the intended slab, and
- where should its bottom lie in relation to the Design Layer it's going in (its Bottom Z).
The "0" of the layer is usually the finished floor – so, assuming the over floor assembly to be 12" thick and allowing half an inch for a floor finish (later), we would ask for the the slab's Bottom Z to be -12 (inches), but only 11.5" thick [1].

Check in a Front view.

This should show you the floor slab with the required thickness, lying just below the floor finish of the current layer.

How to: Cut a hole in the floor for stairs, etc.

Select the floor object, choose the Clip tool (in "Clip out" mode), and clip away where required.