Lock Replacement in Chattanooga, TN

Old houses, old door hardware

St. Elmo's oldest houses, from the 1880s and 1890s, stand along St. Elmo, Alabama and Tennessee Avenues, and hundreds of Craftsman bungalows followed in the 1910s and 1920s. Doors of that age may hold a mortise lock set into the edge of the door, or a bore that a modern deadbolt will not fit without an adapter plate. A different backset or a new strike may also be needed before the lock sits right.

Measure before ordering anything: door thickness, backset, and the size of the existing bore or mortise pocket. Photograph both faces of the lock and the door edge.

Replacement is the right call when a lock is worn past repair, when its cylinder cannot be rekeyed, or when a door has only a spring latch and needs a deadbolt added.

Historic district rules

Chattanooga has four local historic districts, St. Elmo, Fort Wood, Ferger Place and Battery Place, reviewed by the Chattanooga Historic Zoning Commission. Exterior changes in them need a Certificate of Appropriateness, though the St. Elmo guidelines exempt routine maintenance and interior changes.

The door itself draws most of the attention. Section 8 of the St. Elmo guidelines says new doors should not replace historic front doors or street-visible side doors, and allows a front security door only in a full-view design without ornate grillwork. Section 4.3 of the Fort Wood guidelines adds that original hardware and locks should be reused, and that security doors with grates should not hide the original door.

Changing a lock while keeping the historic door is a much smaller step than changing the door. If the new hardware will look noticeably different from the street, ask commission staff before you order it. This is general information, not legal advice.

Measurements and photos to send

Give the neighborhood, which door it is (front, side or the back door off an alley), the lock now fitted, and your measurements and photos. Say whether the house is in one of the four districts. See lock replacement, the Chattanooga page, and lock repair if the original lock may be worth keeping.