Problem
An opaque door makes sense in a vast house of palace, where every room is large enough to be a world unto itself; but in a small building, with small rooms, the opaque door is only very rarely useful.
Solution
As often as possible build doors with glazing in them, so that the upper half at least, allows you to see through them. At the same time, build the doors solid enough, so that they give acoustic isolation and make a comfortable “thunk” when they are closed.
Related Patterns
… this pattern finishes the doors defined by Corner Doors (196) and Low Doorway (224). It also helps to finish Tapestry of Light and Dark (135) and Interior Windows (194), since it requires glazing in the doors, and can help to create daylight in the darker parts of indoor places.
Glaze the door with small panes of glass - Small Panes (239) and make the doors more solid, by building them like Wall Membranes (218) …
Reference for full-text of Pattern: p. 1103low-confidence