Look under Model View Options > Options for GDL Objects (ArchiCAD 14) > Show Minimum Space of Furnishings and Doors.
If you are using 14, then your signature needs an update.
David
David Maudlin / Architect www.davidmaudlin.com Digital Architecture AC29 USA Perpetual • Mac mini M4 Pro OSX15 | 64 gb ram • MacBook Pro M3 Pro OSX14 | 36 gb ram