FM:Interact - Facility & real estate management suite
FreeCAD - An open-source parametric 3D modeler
Wisp by Gensler - Space management software and service by the leader in workplace
SketchUp - 3D for Everyone
FX360 - CAFM Software - Excitech provides CAFM (computer aided facilities management) software solutions that enable you to use information to improve efficiency and simplify complex processes.
LibreCAD - An open source 2D CAD application for Windows, Apple and Linux.