How to Date a House by Its Hardware & Lighting

Paint lies about a house's age, and so does wallpaper, and so does a good realtor. The hardware doesn't. If you want to date a house by its hardware, the record is screwed to the doors and bolted to the windows, and it's usually more honest than the deed.

Start with the fasteners

Slotted screws with off-center, hand-filed slots point to early work. Uniform machine slots come in with mass production. A Phillips head means 1936 or later, without exception, because the Phillips screw didn't exist before then. A door hung entirely on slotted screws was hung before your grandparents picked the paint.

The mechanisms narrow it further

A mortise lock, set into the edge of the door, belongs to a different era than a bored cylindrical lock mounted through its face. Cast-bronze knobs with deep, crisp pattern come from one period; thin stamped knobs from another. Sash locks, window lifts, casement adjusters — each shifted shape by the decade, and because they get used constantly and replaced almost never, they often survive as the oldest untouched thing in the house.

Lighting tells the fastest story

Gas keys and combination gas-electric fixtures bracket the turn of the century. Exposed cloth-covered cord reads earlier than smooth modern insulation. A ceiling box cut in after the plaster set tells you the room was lit before it was ever wired.

But none of this appraises a house. It only dates one. Knowing a lock is 1890s tells you when it was made, not what it's worth. Identification gives you a floor of fact, and a way to tell whether the hardware in front of you came with the house or wandered in later.