How to Value a Commercial Property: A Practical Guide

Most commercial property valuation formulas are simple. Capitalization rate math is a single line. A discounted cash flow model is just a sum of discounted numbers. The formulas were never the hard part.

What separates a defensible valuation from a guess is deciding what belongs in those formulas in the first place — which income is real and repeatable, which comparable sales actually compare, and which of the three classic approaches deserves the most weight for the asset in front of you. Below is a practical walk-through of how appraisers, brokers, and investors actually think through a commercial valuation, from first principles to a worked example.

Market Value vs. Investment Value

Before running any numbers, it helps to be clear about which value you’re actually solving for, because they are not the same thing and mixing them up is one of the most common valuation mistakes.

• Market value is what a typical, informed buyer would pay a typical, informed seller in an arm’s-length transaction — a number that’s meant to hold up regardless of who’s asking.
• Investment value is what the property is worth to a specific buyer, given that buyer’s financing terms, tax position, hold period, and return requirements.

A 1031 exchange buyer under time pressure, a REIT with a low cost of capital, and a local family office with cash on hand can all arrive at very different investment values for the same building — and any of those numbers can diverge meaningfully from market value. Lenders, courts, and most third-party appraisals rely on market value. Buyers and sellers negotiating a specific deal are really talking about investment value, even when they don’t say so explicitly.

Normalize NOI Before You Touch a Cap Rate

Net operating income (NOI) is the engine behind both direct capitalization and DCF analysis, which means an error in NOI doesn’t stay contained — it gets multiplied straight through to the final value. Before applying any cap rate, the income and expense figures on a trailing twelve-month statement or an owner’s pro forma need to be normalized:

• Strip out one-time items. A large insurance settlement, a single bad-debt write-off, or a one-year property tax abatement shouldn’t be treated as recurring income or expense.
• Mark rents to market. Below-market legacy leases understate future income; above-market leases that are unlikely to renew at the same rate overstate it.
• Right-size management fees. An owner-managed property often shows no management line item at all — but a buyer will need to pay for that function, so a market-rate management fee (typically 3–5% of collections) should be added back in.
• Budget realistic reserves. Roof, HVAC, and paving replacement reserves are easy to omit from a seller’s pro forma and easy to forget in underwriting — don’t skip them.
• Confirm vacancy and credit loss assumptions are in line with the submarket, not just the current rent roll.

Two buildings with identical gross income can have meaningfully different values once NOI is normalized this way — which is exactly why relying on a seller-provided pro forma without adjustment is a common way to overpay.

Direct Capitalization vs. Discounted Cash Flow

Direct capitalization divides a single year of stabilized NOI by a market-derived cap rate. It’s fast, it’s easy to explain, and it works well for stabilized, income-producing assets with steady occupancy and no major lease events on the horizon — a fully leased multi-tenant retail center or a well-occupied office building with staggered lease terms, for example.

Discounted cash flow (DCF) analysis projects income and expenses year by year over a hold period (commonly 5–10 years), then discounts each year’s cash flow — plus a projected reversion sale at the end — back to present value using a discount rate that reflects the asset’s risk.

DCF is the better tool when a single stabilized year won’t tell the real story: a building with a major lease rolling in year three, a property that’s partially vacant today but has a credible lease-up plan, an asset needing significant capital improvements before it stabilizes, or anything where near-term cash flow is expected to look meaningfully different from long-term cash flow. In those cases, capitalizing one “typical” year either ignores real near-term risk or bakes in upside that hasn’t happened yet.

How Leases Actually Move the Number

The lease is the asset, in a very real sense — so the details inside it deserve more attention than a simple average rent-per-square-foot figure suggests.

• Lease expirations concentrated in a single year create rollover risk that a cap rate alone won’t capture; a DCF can model the vacancy and re-leasing period explicitly.
• Tenant improvement (TI) allowances and leasing commissions are real cash outflows required to sign a new tenant, and they belong in the cash flow projection for any lease that’s expected to turn over — not just at renewal, but especially for new leases after a vacancy.
• Downtime between leases — the months a space sits empty between a tenant moving out and a new one moving in and paying rent — is often underestimated. In softer submarkets, six to twelve months of downtime for a mid-size commercial space is not unusual, and that lost income needs to show up in the model.

Two properties with the same in-place NOI today can have very different values once lease expiration schedules, TI/commission exposure, and expected downtime are factored in.

Using Comparable Sales Without Over-Relying on Price per Square Foot

The sales comparison approach is intuitive — find recent sales of similar properties and see what they sold for — but price per square foot is a blunt instrument on its own. Two buildings at the same price per square foot can have very different economics if one has a longer weighted-average lease term, better credit tenants, or lower deferred maintenance.

A more reliable comparison looks at the price paid relative to NOI (an implied cap rate), adjusts for differences in location, age, condition, tenant quality, and lease terms between the comparable and the subject property, and weighs the most recent and most physically similar transactions more heavily than older or more dissimilar ones. Comparable sales are most useful as a sanity check against the income approach, not as a substitute for it.

When the Cost Approach Still Matters

The cost approach — land value plus the depreciated cost to reconstruct the improvements — carries less weight for older, income-producing properties, where deriving accurate depreciation is difficult. It matters most for special-purpose properties with few comparable sales or income data (a church, a private school, certain industrial facilities), new construction where replacement cost closely tracks market value, and insurance or lender scenarios that specifically require a replacement-cost figure. For a typical leased office, retail, or industrial building, it’s usually the least influential of the three approaches, but it remains a useful upper-bound sanity check.

Reconciling the Approaches — Not Averaging Them

A common mistake is running all three approaches and averaging the results. Reconciliation is not an average; it’s a judgment call about which approach the market actually relies on for that type of asset, and how much confidence you have in each approach’s inputs.

For a stabilized, multi-tenant income property, the income approach is usually given the most weight, with sales comparison used as a check and the cost approach given little weight. For a single-tenant, owner-occupied building, the cost and sales comparison approaches often carry more weight, since there may be limited independent lease income to capitalize. The reconciliation should explain, in plain language, why the final number sits where it does — not just report three outputs and split the difference.

A Worked Example

Consider a 20,000-square-foot multi-tenant retail center:

• Gross potential rent: $500,000/year
• Vacancy and credit loss (7%): –$35,000
• Effective gross income: $465,000
• Operating expenses (taxes, insurance, CAM, management, reserves): $140,000
• Normalized NOI: $325,000

Direct capitalization: With comparable retail centers trading at a 7.5% market cap rate, indicated value = $325,000 ÷ 0.075 = $4,333,000.

Sales comparison check: Three comparable centers sold recently at implied cap rates of 7.2%, 7.6%, and 7.8%, with the most similar (same submarket, similar tenant mix) at 7.5% — consistent with the direct cap result.

DCF consideration: One anchor tenant occupying 30% of the space has a lease expiring in year two. Because that expiration creates meaningful near-term risk that a single stabilized year won’t reflect, a DCF is run over a 7-year hold, explicitly modeling nine months of downtime, a $15/SF TI allowance, and a leasing commission at renewal — producing a present value of approximately $4,100,000, somewhat below the direct cap indication because of that rollover exposure.

Reconciliation: Given the material lease rollover risk the direct cap approach doesn’t capture, more weight is placed on the DCF result, with the direct cap and sales comparison figures used as supporting checks. Final indicated value: approximately $4,100,000–$4,150,000.

This is the kind of judgment call that separates a defensible number from a formula plugged in without context — and it’s exactly where local market knowledge (submarket cap rates, realistic downtime, actual TI costs) makes the difference.

Get a Second Set of Eyes on Your Number

Whether you’re buying, selling, refinancing, or just want to understand what a property in San Juan or elsewhere in Puerto Rico is really worth, the Two20 Group team works through this process daily across office, retail, industrial, and multifamily assets. If you’d like a market-informed opinion of value, reach out to our team — we’re happy to talk through the numbers.