Duplex house plans — two separate homes under one roof on a single plot

A duplex is two separate homes under one roof, each with its own entrance and a shared plot. It suits relatives living side by side just as well as two completely independent families.

Equal or unequal halves

Depending on the layout and needs, the halves can be equal or unequal. The symmetrical version — mirrored homes — usually serves two independent families. The unequal one is more often for an extended family living together: a family with children in the larger part, the older generation in the smaller. The plan is not obliged to be symmetrical, and that is exactly what makes the format flexible.

Vertical split across floors

A two-storey house can also become a duplex when the floors are split into separate apartments reached through a shared hallway. It is a different scenario from the classic side-by-side pair, worth considering on a narrow plot or where only a compact volume fits.

Density and the plot

The main advantage of a duplex is the efficient use of land. A 240 m² duplex from our "6 sotok" project fits comfortably on a 600 m² lot — something two separate houses would rarely manage with the required fire-safety gaps. It is one of the best formats when there is not enough land for two and building two separate houses side by side makes no sense.

How a duplex differs from a townhouse

A duplex is two units under one roof. If you need a row of three or more, see the townhouse section — different economics, a different relationship with the plot.

Related sections

Townhouses · two-storey · narrow plots · full catalogue

Choose a duplex plan

Plans in this category are designed by Alexei Biryukovich, architect at AkvilonPro with over 45 years of experience. Choose a ready-made duplex plan or order an adaptation to your family and plot — get in touch.