To import a roof

Click the Import icon.
The Import Roof dialog box opens.
Do one of the following:

Type in the path and file name of the DGN file you want to import the roof from.

or
Click the browse button, and browse the disk for the DGN file you want to import the roof from.
Select the DGN model containing the roof to import from the Models drop-down list.
Selecting the model updates the Levels list.
Select the levels you want to be copied. You can select or deselect all by clicking the all on and all off buttons.

Note: If you choose not to import levels, the roof will be imported and copied to the currently active level.