SketchUp

Easy 3D modelling for architecture and design.

About SketchUp

In SketchUp’s own words: “Bring your vision to life with SketchUp. Design in 3D, from concept to construction, with intuitive tools for architects, designers, and builders.”

SketchUp has a free plan.

People switching from AutoCAD often consider SketchUp.

SketchUp is an alternative to

AutoCADSee all AutoCAD alternatives

Similar to SketchUp

Autodesk FusionCloud CAD/CAM/CAE with a free personal-use license.
BricsCADDWG-compatible CAD with perpetual licenses.
DraftSightProfessional 2D CAD from Dassault Systèmes.
FreeCADFree, open-source parametric 3D CAD.
LibreCADFree, open-source 2D CAD.

Listed for information; LaunchStall isn’t affiliated with SketchUp. The quoted description comes from sketchup.com. Features and plans change — check the official site for current details.