What are Comps (Sales and Rent Comps) in CRE?
Comparable transactions used to establish the market value of a property — the empirical foundation of every BOV, OM, and pricing conversation a broker has.
Key takeaways
- Comps are comparable sales or lease transactions used to establish market-based pricing for a property — they're the empirical backbone of every valuation and marketing document a broker produces
- Which comps you select, which you exclude, and how you contextualize each one determines whether your pricing opinion is accepted or challenged
- Three well-selected, thoroughly explained comps outperform a table of fifteen with no interpretation — buyers discount data dumps
- Distressed sales, entity-level transactions, and non-arm's-length transfers should almost always be excluded from a comp set, with the exclusions explicitly noted
The plain-English definition
Comps — short for comparables — are recent transactions involving properties similar enough to the subject property that their sale prices or lease rates can be used as evidence of market value. In commercial real estate, there are two primary comp types: sales comps, which establish value benchmarks based on what buyers have paid for similar properties, and rent comps, which establish market rent levels based on what tenants have agreed to pay in comparable spaces.
A sales comp is most useful when it shares key characteristics with the subject property: similar asset class, comparable size (in units, square feet, or acres), comparable vintage and condition, proximity (same submarket or comparable submarket), and a transaction date recent enough to reflect current market conditions. The tighter the match across those dimensions, the more weight the comp carries. A 2019-vintage, 24-unit multifamily that sold six months ago three blocks away is a strong comp. A 2004-vintage, 85-unit asset that sold two years ago in a different submarket is a weak one — useful only as directional context.
Rent comps follow the same logic applied to lease transactions: comparable space type, similar size, same submarket, recent execution date, and comparable lease structure (NNN, gross, modified gross). For properties with below-market in-place rents — a common value-add investment thesis — rent comps are the primary evidence that market rents support the proforma projection. If the rent comp set shows executed rents 15% above current in-place rents, the proforma argument becomes credible. If the rent comps show the market is already at in-place levels, the upside story disappears.
How brokers use it in practice
Comps are not just data points — they're arguments. The broker who selects, presents, and contextualizes comps most effectively controls the pricing conversation. That's true in a BOV, where you're arguing for a specific value range to a seller. It's true in an OM, where you're arguing to buyers that the asking price reflects fair market value. And it's true in a listing pitch, where your comp work is the primary evidence of your submarket expertise.
Effective comp selection requires judgment, not just a database search. You should include comps that are genuinely similar on the most value-relevant dimensions and exclude those that aren't — with clear notations explaining both decisions. A distressed sale at 15% below market is not a comp that supports your pricing; it's an outlier that a buyer will cite to push your price down. Acknowledge it, explain why it's excluded, and move on. Ignoring it entirely is worse — it makes your analysis look incomplete.
You can manage your sales and rent comp database and pull deal-specific comp sets using managing sales and rent comps in IntellCRE, which lets you build a running comp library by submarket so that each new BOV or OM draws from current, organized data rather than a fresh CoStar search every time. The time this saves compounds over a full pipeline: if you're producing 12–15 BOVs per quarter, a clean comp library cuts the research phase by 30–60 minutes per document.
For presentation, three to five comps with a paragraph of context on each one outperforms a table of fifteen every time. The context is the work — explaining the cap rate, the price per unit, the occupancy at sale, and why each comp is relevant to your pricing opinion. Buyers can read a table. What they can't do without you is interpret it.
Common misconceptions
The most common misconception is that more comps signal more rigorous analysis. They don't. A table of fifteen comps with no annotation signals that the broker exported a CoStar list without editing it. Sophisticated buyers discount comp presentations that feel like data dumps — they want to see evidence that the broker has looked at each transaction and formed a view about its relevance. Three comps with real interpretation are worth more than fifteen without any.
The second misconception is that all closed transactions qualify as comps. They don't. Distressed sales (foreclosures, receiverships, forced liquidations), entity-level transfers (where the entire ownership entity sold, not just the property), and non-arm's-length transactions (family transfers, partnership buyouts at non-market prices) should typically be excluded from a comp set used to establish market value. If they're in the market record and a buyer is likely to find them, address them directly — explain the context and why they don't reflect arm's-length market pricing for a stabilized asset. Not addressing them is the mistake.
The third misconception is that rent comps and sales comps can be used interchangeably as value evidence. They can't. Sales comps establish what buyers have paid — the demand side of the market. Rent comps establish what tenants have paid — which drives the NOI that supports pricing. You need both: rent comps to validate the proforma revenue assumptions and sales comps to validate the cap rate at which that NOI is valued. Using only one without the other leaves a gap in your analysis that buyers will find and exploit. With AI underwriting that integrates both comp types into a single financial model, the two sets stay consistent from the first draft through the final OM.
Frequently asked questions
How recent do comps need to be to be useful?
In a stable market, transactions within the past 12–18 months are generally acceptable. In a market with significant recent rate movement or value volatility, tighten to 6–12 months. Older comps can be included for directional context if clearly labeled, but shouldn't carry primary weight in a pricing opinion. When the market is moving quickly, recency matters more than similarity.
What's the difference between a sales comp and a rent comp?
A sales comp is a closed property sale used to establish value benchmarks — price per unit, price per square foot, cap rate at sale. A rent comp is an executed lease transaction used to establish market rent levels. Sales comps support your pricing argument; rent comps support your proforma revenue assumptions. Both are essential for income-producing properties where the buyer is underwriting to projected NOI.
How do I handle a comp that hurts my pricing opinion?
Address it directly. Identify the characteristic that makes it a weak comp — distressed sale, inferior location, older vintage, lower occupancy at sale — and explain the adjustment. Ignoring a comp that a buyer will find in CoStar is far more damaging than acknowledging it and contextualizing it. Buyers trust brokers who show their work, including the parts that don't favor the pricing.
Can I use listing prices (not closed sales) as comps?
Active listing prices are not comps in the strict sense — they represent asking prices, not executed values. They're useful as directional context (e.g., "current listings in the submarket are priced at $X per unit") but should never be substituted for closed sales in a comp set. Buyers know the difference, and presenting asking prices as market evidence will undermine your credibility with any experienced underwriter.