You can use the Create Automatically tool to automatically create spaces in an architectural model that is opened in Revit.
Spaces are automatically created for enclosed areas greater than 0.25 sq. ft. If the area where the space is created contained a room component, then the space is set to Occupiable. Spaces are created on the current level according to the parameters on the Options Bar. The Space components added to the model are named numerically.
Click Highlight Boundaries to show the outline of the bounding components that will enclose the spaces created.