The buildings and the hardware
The local mix of buildings changes what the locks look like. Older single-family doors in this township often have solid wood doors with mortise locks or full-backset deadbolts; you’ll see heavy cast escutcheons and three-screw strike plates. Apartment units and newer rental properties tend to use bored-cylinder locks in hollow-core doors and lighter latch assemblies that require reinforcement for security. Storefronts usually have aluminum frames and rim cylinders or exit-device hardware, which call for different keyways and sometimes shim or latch-bolt adjustment. Knowing the door and frame tells us which part to fit and how to fasten it.