KO Appraisal
Guide

What is net operating income?

Net operating income is what a property earns after operating expenses but before financing, depreciation, and income tax. It is the numerator of nearly every income-based valuation, which makes it the number most worth getting right, an error here scales straight into value, multiplied by roughly sixteen at a 6% cap rate.

Building it up, line by line

NOI is constructed in a fixed order, and each step exists to remove an optimism that a raw rent roll contains:

  • Potential gross income: every unit at market rent, fully occupied for the year. A theoretical maximum, not a forecast.
  • Less vacancy and collection loss: an allowance reflecting what the market actually sustains, not what the property happens to be doing this month. This is where stabilised analysis departs from a snapshot.
  • Plus other income: parking, storage, laundry, signage, cost recoveries and reimbursements from tenants. Recurring only; a one-off lease-termination payment is not income the next owner inherits.
  • Equals effective gross income.
  • Less operating expenses: property taxes, insurance, utilities not recovered from tenants, management, repairs and maintenance, and the reserve for replacement.
  • Equals net operating income.

What is deliberately excluded, and why

The exclusions define the measure. NOI describes the property’s earning capacity, so anything belonging to a particular owner rather than to the real estate is left out.

  • Debt service. Financing is a decision of the owner, not an attribute of the building. Two buyers with different loans hold the same asset.
  • Depreciation and amortisation. Accounting allocations, not cash costs of operating.
  • Income tax. Depends entirely on the owner’s circumstances.
  • Capital expenditure. Distinguished from repairs: replacing a roof is capital, patching one is a repair. Capital items are handled through the replacement reserve, not expensed in the year incurred, so a single large project does not distort one year’s income.
  • Leasing commissions and tenant improvements. Real costs, but lumpy and tied to lease events. Normally modelled in discounted cash flow rather than deducted from a stabilised NOI.

The reserve for replacement, and why owners leave it out

Building components wear out on schedules longer than a year, roofs, HVAC, elevators, parking surfaces. The reserve spreads their eventual cost across the years of service so that annual income reflects the true cost of sustaining it.

Owner-prepared statements frequently omit it, not always innocently: leaving it out raises reported NOI, and at a 6% cap rate every dollar removed adds about sixteen to the apparent value. An appraiser reconstructs the reserve from the components’ costs and remaining lives regardless of whether the owner recorded one.

Reconstructing an operating statement

The statement an owner supplies is a starting point, not an input. Appraisers normalise it against market evidence, because an owner’s actual expenses reflect their own management choices rather than what the property requires.

  • Remove non-recurring items: a legal settlement, a one-time repair, an insurance recovery.
  • Remove owner-specific costs that would not transfer: an above-market management fee paid to an affiliate, or personal expenses run through the property.
  • Add costs the owner absorbs but a buyer would incur. Most commonly a market management fee where the owner self-manages for free.
  • Reassess property taxes where a sale would trigger reassessment. In California this matters directly: under Proposition 13 a change in ownership generally re-establishes the assessed value at current market value, so the buyer’s tax burden may exceed the seller’s substantially. Using the seller’s historic tax figure overstates the income a buyer will actually receive.
  • Test each remaining line against comparable properties, and investigate anything materially out of range rather than accepting it.

Common questions

How do you calculate net operating income?
Start with potential gross income at market rent, deduct a market vacancy and collection allowance, add recurring other income to reach effective gross income, then deduct operating expenses including a reserve for replacement. Do not deduct mortgage payments, depreciation, or income tax.
Is net operating income the same as EBITDA?
They are analogous but not identical. Both measure operating performance before financing and tax, but NOI is specific to real estate, is computed after a reserve for replacement, and excludes corporate overhead that EBITDA would capture. Treating one as the other misstates both.
What is the difference between operating income and net income?
Net income is what remains after everything. Financing, depreciation, and tax. Net operating income stops before all three, which is exactly what makes it useful for valuation: it describes the property rather than the owner’s financing and tax position.
How does NOI affect cap rate?
Mechanically, for a fixed sale price a higher NOI produces a higher computed cap rate. This is why unverified NOI figures are dangerous when extracting rates from comparable sales. An overstated NOI on a comparable inflates the extracted rate, and applying that inflated rate to a subject property then undervalues it.
Should NOI use actual or market figures?
Stabilised figures grounded in market evidence, with actuals as a reality check. Where actual performance departs from the market, the appraisal explains why and whether it is temporary or structural. A property underperforming because of poor management is worth more than its current income suggests; one underperforming because of a structural shift in demand is not.
Who wrote this Kevin O'Brien, MAI, SRA. California Certified General Real Estate Appraiser #3005065, issued by the California Bureau of Real Estate Appraisers (BREA). Practicing in San Diego. This page reflects how these assignments are actually handled, not a summary of other people's summaries.
Where this applies Appraiser licensing is state-specific, there is no national appraisal licence, so appraisal engagements here are California properties, primarily San Diego County. The valuation methodology and the federal tax rules described above apply anywhere in the United States; if your property is in another state, you need an appraiser credentialed there, and this page should still tell you what to ask them for.

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