Cap Rates, NOI, and How Commercial Buyers Read a Building

Commercial real estate looks complicated from the outside, but most pricing comes down to two figures working against each other: net operating income (NOI) and the capitalization rate. NOI is what the building earns after operating expenses but before debt and taxes — rent collected, minus the cost of keeping the property running. The cap rate is the return a buyer expects on that income, expressed as a percentage. Divide NOI by the cap rate and you get value.

The mechanics matter because they reveal how value actually moves. A building earning $300,000 in NOI at a 6% cap rate is worth $5 million. Lift NOI to $360,000 through higher rents or lower expenses and, at the same cap rate, the value jumps to $6 million. That leverage is why operators obsess over occupancy, lease structure, and expense control: small improvements in income compound into large swings in value.

Cap rates themselves are a read on risk and demand. Lower cap rates mean buyers will accept less current income because they trust the location, the tenant, or the growth ahead. Higher cap rates signal more perceived risk — a weaker market, a shorter lease, a tenant whose credit is uncertain. When interest rates rise, cap rates generally drift up too, which pushes values down even when a building's income hasn't changed at all.

For an owner preparing to sell, the implication is direct: the work happens at the income line. Renewing tenants early, removing below-market leases, and trimming controllable expenses all raise NOI before a buyer ever runs their own numbers. For a buyer, the discipline is to underwrite the income you can defend — actual signed leases and real expenses — rather than the optimistic pro forma on the brochure. The building doesn't lie; the assumptions around it sometimes do.