Doors play a vital role in the aesthetic and function of a house. First sight as you approach should make plain how you get in.
In traditional architecture the front door is presented central to the front elevation. The design can be elaborated with a porch. The status of the house can be shown in the door/porch design. The status can be defined by its appearance from the modest vernacular of a tiled lean-to or the formal classical of a columned pediment.
As a design ingredient the front door is a design opportunity to display the style and character of a house.