Jettying's a building technique used in medieval timber frame buildings in which an upper floor projects beyond the dimensions of the floor below. This has the advantage of increasing the available space in the building without obstructing the street. Jettied floors are also termed jetties. Structure A jetty's an upper floor that depends on a cantilever system in which a horizontal beam, the jetty bressummer, supports the wall above and projects forward beyond the floor below (a technique als… (More on Jettying)