According to Ernst Neufert's "Architects' Data," the size of doors varies depending on their intended use and the type of room they provide access to. The minimum clear width for a door to be passable by a person is 55 cm. In residential buildings, the typical clear opening widths of doors are as follows:
- Single-leaf doors for rooms: Approximately 80 cm.
- Bathroom doors: Approximately 70 cm.
- Entrance doors to flats: Minimum 90 cm.
- Front doors: Up to 115 cm.
- Double doors for rooms and front doors: Approximately 170 cm to 225 cm.
The clear opening height of internal doors should be a minimum of 210 cm【7†source】.