The buildings and the hardware
The mix of buildings in Berwyn affects the hardware you find on site. Older single-family houses and twin cottages often still have mortise-style locks or oversized kit-based deadbolts that require different tools and parts than modern cylindrical locks. Apartment buildings and multiunit conversions tend to use keyed-alike systems, simple cylinder swaps, or master key work, which calls for careful pinning and record-keeping. Small storefronts and professional offices usually have commercial cylindrical locks, exit devices, and sometimes electric strikes or magnetic locks, so the job shifts from a simple cylinder change to fitting hardware that meets heavier use and different mounting conditions.