The phrase "the Smiths' house" in Spanish is "la casa de los Smith." In this construction, "casa" means "house," and "de los Smith" indicates possession, translating to "of the Smiths." If the family name were more common in Spanish, it might change to reflect pluralization, but "Smith" remains the same.
The house sign should say "The Smiths" to indicate that the house belongs to the Smith family. Using "The Smith's" would be incorrect, as it implies possession or belonging to a single individual named Smith.
house = casa
'in-house' - interior, interno/a
el casa = a house
"hen house" translates to, "gallinero" in Spanish.
en la casa del mayordomo is the spanish for at the butler's house
old house = casa vieja.
A beautiful house in Spanish is "Una casa hermosa".
at her house
tu casa es mi casa
casa nueva
Casa blanca