洋 ('foreign/Western') +
房 ('house'). The classic image is the
上海老洋房 of the former French Concession — late-Qing and Republican-era villas built by Westerners or Westernised Chinese, with sloped roofs, fireplaces, and gardens. Today
老洋房 are heritage-protected luxury real estate. The closely related
石库门 refers to the lane-house tenement style instead.
