The buildings and the hardware
The built environment affects the hardware we use. Many doors in this area are older solid-wood or original-frame units with mortise locks or rim cylinders, so jobs often mean fitting compatible cylinders, fitting a new latch, or modifying trim to accept modern deadbolts. Where there are multi-unit buildings you’ll see more narrow stile doors and surface-mounted closers; that changes screws, fasteners, and the approach to reinforcing the frame. Storefronts and commercial doors tend to have exit devices or keyed leversets that require different parts than a suburban house, and retrofit work comes up a lot.