The exterior of the Otto's house is the "Paramount House" on Colonial Street on the Universal Studios Hollywood backlot. It was previously used as the Cleaver's house in Leave It to Beaver (1957) and as the Welby residence in Marcus Welby, M.D. (1969).
The house on American Housewife is a replica of the "Paramount House" on the Universal Hollywood Backlot. The original Paramount House sits boarded up on a corner of the same Universal backlot. Its been there for years.