A duplex is two dwellings on one plan — side-by-side or stacked — at roughly 800–1,500 sq ft per unit. Quoting both units off one drawing is exactly where rooms get double-counted or missed.
Side-by-side duplexes are usually near mirror images sharing a party wall; stacked ones repeat the same footprint per floor. Mirrored does not mean identical: closets, stairs and bump-outs often differ, and the party wall is thicker than interior partitions, so copying one unit’s numbers onto the other quietly misstates it.
The reliable way to measure any duplex plan is off the drawing itself: calibrate against a printed dimension line, then trace each room along the inside face of the walls. Measure each unit as its own plan even when they look mirrored, and export a CSV per unit so the client can split costs cleanly. Trace to the inside face of the party wall like any other wall.
PlanTape does the tracing for you. It detects every labelled room and the scale line in under two minutes, you fine-tune the corners, and the per-room areas and baseboard perimeters export as a CSV — in square feet and feet.
Typically 800–1,500 sq ft (74–139 m²) of internal floor area, with 2–3 bedrooms per unit, two units. Exact size varies by year and builder; the floor plan for your specific unit is the only reliable source.
Upload the floor plan PDF to PlanTape: it traces each room along the inside face of the walls and calibrates scale from a printed dimension — feet-and-inches dimensions like 24′-6″ are read natively. Measure each unit as its own plan even when they look mirrored, and export a CSV per unit so the client can split costs cleanly. Trace to the inside face of the party wall like any other wall. Then export per-room areas and perimeters as CSV, in sq ft and feet.
Side-by-side duplexes are usually near mirror images sharing a party wall; stacked ones repeat the same footprint per floor. Mirrored does not mean identical: closets, stairs and bump-outs often differ, and the party wall is thicker than interior partitions, so copying one unit’s numbers onto the other quietly misstates it.
