An attached single-family residence with three levels of finished living area: lower level, intermediate level and upper level. The lower level is immediately below the upper level as in a two-story residence. The intermediate level, adjacent to the other levels, is built on a grade approximately one-half story higher than the lower level. Each tri-level rowhouse unit is one of a group of two or more units joined by common walls. Such units never have units above or below, always have individual exterior walls, and never have more than two walls common with adjacent units. A Center Unit is inside a row, with other units on either side. This style is especially common throughout Canada.