Other major cities do not use the term duplex in their zoning or land-use bylaws. San Francisco and Vancouver use the term Two-family dwelling. Winnipeg uses the term Dwelling, two-family. The definitions of these terms do not specify the physical relationship between the two dwelling units in the building. In cities such as Buffalo, Detroit and Chicago the term Two-flat is used and defines it as a "residential building that contains 2 dwelling units located on a single lot. The dwelling units must share a common wall or common floor/ceiling."