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
QCAD - QCAD is an application for computer aided drafting in 2D.
FreeCAD - An open-source parametric 3D modeler
NttCAD - Free 2D/3D CAD software, easy to use and multi-platform
DraftSight - Discover Dassault Systèmes®' DRAFTSIGHT™ Professional CAD software that lets you create, edit, view and markup any kind of 2D drawing. Learn more here.