The Sears kit house, and its rivals from Aladdin and Montgomery Ward, let you buy a home the way you bought a coat: from a catalog. For roughly the first third of the twentieth century, these companies sold complete kit homes, every board, nail, fixture, and fitting numbered and shipped by rail, to be assembled on your own lot. Tens of thousands went up, and many are still standing, often unrecognized by the people living in them.
How to spot one
The kit house was mail-order standardization applied to shelter. You chose a model from the catalog, the company shipped the parts, and a local crew put it together from the plans. Because everything came from one supplier in known models, kit houses carry a consistency custom-built houses don't. The same model, built in different states, used the same millwork, hardware, and fixtures.
That consistency is how you identify them. Kit homes often carry marks: numbered framing lumber, shipping stamps, hardware and millwork matching a known catalog model. Match the part to the catalog and you can often date and name the house.
For salvage, this cuts an interesting way. A part from a kit house isn't one-of-a-kind; it was made in quantity for a mass-market model. But that's exactly what makes it useful for matching, because so many identical ones were built.
Salvager's Note: Suspect a kit house? Check the framing lumber for stamped part numbers and shipping marks, and match the millwork and hardware to a known catalog model. If it's a kit home, your missing part was made by the thousand, so a match is far more findable.