noun
one house; the same house
Refers to a single house, or to the same house shared by multiple people. Often used in contexts like living under one roof.
彼らは一つ家に住んでいる。
They live in the same house.
一つ家に三世代が暮らすのは大変だ。
It's tough for three generations to live under one roof.
noun
A standalone house, not attached to other buildings. Less common than 一戸建て (いっこだて) in modern Japanese.
この辺りは一つ家が多い。
There are many detached houses in this area.