How do multi-unit buildings work?
When you add a duplex, triplex, or apartment building, the wizard asks whether you own a single unit or the entire building.
If you own the building, each unit gets its own rent, tenant, and lease. Property pages let you switch between the whole building and a single unit, so budgets, rent history, and expenses can be viewed per unit.
Building-level costs like the mortgage or insurance stay at the building; unit-level items like a lease or a repair in one unit are tagged to that unit.