Obviously the variety of door situations, sizes, functions etc. are infinite, but these are some of the factors which need to be considered: Is it a fire, smoke or emergency escape door? How heavy is the door and what are it’s dimensions (height x width x thickness)? What is the door’s construction and are there any unusual features to take into account? Where is the door located e.g. internal or external, near the coast or in a swimming pool? What level of use/abuse will the door be subjected to e.g. office, hospital or school corridor? What items of door hardware are to be fitted which may affect the hinge performance e.g. door closers or door stops? Any other unusual features e.g. an arched door, bifolding etc?