Hurlinges are popular with carpenters as they do not require cutting into the frame or the door. Additionally they have lugs shaped into the knuckle of the hinge that allow simple lining up and fitting. Both points combined enable doors to be fitted quickly and accurately, they are therefore a popular choice with the carpentry trades, specifically house builders and 2nd fix carpenters.
Flush hinges are mainly used for lay-over doors, particularly when MDF or particle boards are being used.