Where does “double house” come from?

double house (English) comes from English doublé, from French doublé, from Middle French double, from Old French doble, from Latin dūplus, from Proto-Italic *duplos — double.

Ancestry of “double house”, step by step

double house traces back through two separate lines of ancestry.

via English doublé

StepLanguageWordMeaning
1EnglishdoubléA compound attack that deceives the opponent's...
2Frenchdoublédouble, brace, pair; double; doublé
3Middle Frenchdouble
4Old Frenchdobledouble
5Latindūplusdouble (twice as much, or as big)
6Proto-Italic*duplosdouble

via English House

StepLanguageWordMeaning
1EnglishHouseA particular chamber of political representation
2Middle Englishhoushouse, residence; house of worship, temple;...
3Old Englishhūsdwelling, shelter, house; house
4Proto-West Germanichūshouse
5Proto-Germanichūsąhouse
6Proto-Indo-European(s)kewH-to cover, bedeck; cover
Every word from Proto-Italic *duplos