A porch is a structure attached to a building, forming a covered entrance to a vestibule or doorway. It is external to the walls of the main building proper, but may be enclosed by screen, latticework, broad windows, or other light frame walls extending from the main structure.
There are various styles of porches, all of which depend on the architectural tradition of its location. All porches will allow for sufficient space for a person to comfortably pause before entering or after exiting the building. However, they may be larger. Verandahs, for example, are usually quite large and may encompass the entire facade as well as the sides of a structure. At the other extreme, the Grand Hotel on Mackinac Island, Michigan has the longest porch in the world at some 660 feet in length.
When covered, a porch not only provides protection from sun or rain but may also form, in effect, an extra exterior room that may accommodate chairs, tables and other furniture, to be used as living space. Screens are often used in some areas to exclude flying insects.
Porches typically are architecturally unified with the rest of the house, using similar design elements as the rest of the structure, and may be integrated into the roofline or upper stories.