How to Stress Test a Duplex Before You Buy It in Albuquerque

A guide to checking whether a duplex's numbers hold up under realistic rent and vacancy assumptions, not just optimistic ones.

Most duplex listings come with a rent number attached, usually the highest one the seller can defend. Before you treat that number as real, run it through a slower scenario. Ask what the unit would rent for if it sat vacant for a month or two, if the next tenant negotiated harder, or if the market softened for a year. If the property still covers its costs under those conditions, you are looking at a defensible deal. If it only works at the listed rent, you are looking at a bet.

Start with the actual condition of the building, not the staged version. Roof age, plumbing material, panel capacity, and the state of each unit's mechanical systems matter more than paint and staging. A duplex that needs a new roof in two years is not the same investment as one that does not, even if the rent roll looks identical on paper.

Next, separate current rent from market rent from realistic rent. Current rent is what the existing tenant pays. Market rent is what an optimistic listing agent thinks it could fetch. Realistic rent is what you could count on if you needed to fill that unit in a normal, unremarkable month. Build your offer around the third number, not the first two.

Run your exit before you run your entry. Ask who would buy this property from you in five or ten years, and under what conditions. A duplex that only makes sense to an investor chasing appreciation is a different purchase than one that would still cash flow for a buyer who wanted steady rent. Know which one you are buying.

Finally, get comfortable with walking away. Most duplexes that come across your desk will not survive this kind of scrutiny, and that is the point of doing it. The properties that do survive are usually less exciting to look at and more boring to own, which in this business is a compliment.