When choosing a door model and extra accessories it is important to remember that the main door structure consists of several components:
- Door frame — the frame installed in the door opening to which the flat part is attached;
- The flat part — the opening part of the door;
- Finish casing — the component applied around the perimeter of the door-frame to cover the gap between the door frame and the wall;
- Door panel — the sheet filling the opening in the skeleton structure;
- Finish hardware — the knob, hinges, lock, latch, peep-hole, etc.;
- Threshold — installed to improve the acoustic and heat insulation properties of the door.
The integral parts of the door may include: glass, finish casing (decorative borders), threshold, sealing gasket, lock, (one of several types), door knob.
The size of the door opening is determined by three dimensions: height, width and thickness in millimeters.