Fenster
Before we go into the different types of Windows and Doors we will review the way they are classified. Both are subsurfaces of walls. They can be both interior or exterior. While interior windows have more properties and exterior doors have all the properties of interior ones. This document will apply to exterior doors. Doors can be opaque or transparent. Opaque doors look like ceilings and floors as well as walls. Transparent doors are the exact opposite.
