Reference:

Autodesk Maya 2020 Quick Tip: Setting up reference images for modeling
Autodesk Maya 2020: Architectural Composition Beginner tutorial 1: Base-01
Autodesk Maya 2020 Architectural Composition Base Beginner tutorial 2
Autodesk Maya 2020: Architectural Composition Beginner tutorial 3: Gothic window
Autodesk Maya 2020 Architectural Composition Beginner tutorial 4: Round window
Autodesk Maya 2020 Architectural Composition Beginner tutorial 5: Semi round window
Autodesk Maya 2020 Architectural Composition Beginner tutorial 6: Door
Autodesk Maya 2020 Architectural Composition Beginner tutorial 7: Tower
Autodesk Maya 2020 Architectural Composition Beginner tutorial 8: Side Entrance