It's good easy to learn to use for MEP Drawings Brics CAD can use Cad & BIM extension file DWG # Philemon _Dubai
LibreCAD - An open source 2D CAD application for Windows, Apple and Linux.
SketchUp - 3D for Everyone
ArchiCAD - ArchiCAD 16 enables BIM modeling with a new green approach to planning. Create anything you need with ArchiCAD's flexible new features for design.
FreeCAD - An open-source parametric 3D modeler
e-Builder - e-Builder is a construction program management solution that manages capital program cost, schedule, and documents.
DraftSight - Discover Dassault Systèmes®' DRAFTSIGHT™ Professional CAD software that lets you create, edit, view and markup any kind of 2D drawing. Learn more here.