Sale Comp vs. Lease Comp: A Glossary for Commercial Real Estate Due Diligence

Sale Comp vs. Lease Comp: A Glossary for Commercial Real Estate Due Diligence covers the two comp types every underwriting file depends on. The difference between them determines whether a valuation holds up under scrutiny. A sale comp tells you what a property traded for. A lease comp tells you what the space inside that property actually rents for. Investors and lenders who treat these as interchangeable get surprised at closing. Appraisers know the feeling too.

This glossary breaks down both comp types and the terms embedded in each. It also shows how they fit together in a due diligence file.

Key Takeaway

A sale comp answers “what did this asset trade for,” while a lease comp answers “what is the income behind that price actually worth.” Due diligence requires both: sale comps benchmark price and cap rate against the market, and lease comps stress-test the rent roll, rollover risk, and mark-to-market upside that justify the price. Neither comp type substitutes for the other.

What Is a Sale Comp?

A sale comp is a record of a completed property transaction, including sale price, price per square foot, cap rate, buyer and seller identity, and closing date. It answers a single question: what did a comparable asset sell for, under what terms, at what point in the market cycle.

A complete sale comp file typically includes:

• Sale price and price per SF: the gross transaction value, normalized for size.
• Cap rate: net operating income divided by asset value, the standard yield metric used to compare pricing across deals.
• Buyer and seller: ideally resolved to the actual investment entity, not just the transacting LLC.
• Closing date and financing terms: including whether the deal involved assumed debt, seller financing, or an all-cash close.

Sale comps are the backbone of appraisal work and acquisition underwriting. They tell an investor what the market has already paid for a similar asset. What they do not tell you is why that asset generated the income it did, or whether that income is durable. For that, you need the lease comps sitting underneath the sale.

Source: Data from CompStak’s proprietary database. Click here to learn more.

What Is a Lease Comp?

A lease comp is a record of a single lease transaction between a landlord and a tenant, capturing rent, term, concessions, and space characteristics at the deal level. It answers a narrower but more operationally important question: what is this specific tenant actually paying, on what terms, and how does that compare to what the market would pay today.

A lease comp typically includes:

• Starting rent: rent per square foot in the first year of the lease, before escalations.
• In-place rent: the rent currently being paid on that lease, which can differ substantially from starting rent depending on how far into the term the lease is.
• Net Effective Rent: the average monthly rental cost net of concessions, a truer read of landlord economics than face rent alone.
• Adjusted Effective Rent: the grossed-up annual effective rent per square foot, incorporating both free rent and Work Value (CompStak’s field name for tenant improvement allowance, or TI).
• Free rent: the number of months at no rent, often expressed as a percentage of total lease term.
• WALT: weighted average lease term, the average remaining lease duration across a rent roll, weighted by square footage.

Lease comps are the raw material behind rent rolls and market rent studies. They’re also the backbone of rollover risk analysis. A single lease comp tells you about one tenant. A large enough sample of lease comps, aggregated across a submarket or asset class, is what CompStak’s Columbia CompStak Rent Index (CCRI) is built from, developed in partnership with Columbia Business School.

Source: Data from CompStak’s proprietary database. Learn more at compstak.com.

Sale Comp vs. Lease Comp: What’s the Difference?

The core difference is scope. A sale comp values an entire asset in one transaction; a lease comp values one tenant’s occupancy of one piece of that asset. Sale comps move at the pace of the investment sales market. Lease comps move at the pace of the leasing market, which is faster and far more granular.

A sale comp without underlying lease comps is a price with no explanation. A set of lease comps without a sale comp is a rent roll with no market context for exit pricing. Due diligence files that only pull one comp type are incomplete by definition.

Why Due Diligence Needs Both Comp Types

Sale comps and lease comps answer different questions, and skipping either one leaves a gap in the underwriting. A price that looks cheap on a per-square-foot basis can be justified entirely by leases that are short-term and priced below market, set to roll down at renewal. Lease comps are what surface that risk before closing, not after.

An investor relying only on comparable sale comps from three or four years ago, without checking current lease comps for rent trajectory and concession trends, would be underwriting against stale assumptions. Longer hold periods mean the lease roll matters more, not less, to the eventual exit.

Lenders face the same problem from a different angle. A cap rate from a sale comp tells you what the market paid for a dollar of NOI. It does not tell you whether that NOI is at risk from lease expirations in the next 24 months, which is exactly what a WALT calculation and an expiration schedule pulled from lease comps will show.

How CompStak Verifies Sale and Lease Comps

CompStak sources both comp types through the CompStak Exchange, a free network where more than 40,000 verified CRE professionals contribute comps in exchange for data access. Every comp submitted, whether a lease or a sale, runs through a multi-step verification process: machine learning models flag statistical anomalies, and a team of CRE data analysts reviews each record before it is published.

For sale comps specifically, CompStak resolves the transacting entities to their True Buyer and True Seller, the actual investment entity behind a deal rather than the single-purpose LLC that shows up on the deed. That matters for institutional due diligence because tracking a sponsor’s real acquisition and disposition history across a portfolio requires knowing who is actually on the other side of the table, not just which shell entity signed the closing documents.

For lease comps, the same entity resolution applies to landlords and tenants through CompStak’s tenant and ownership data, which is how lease-level data rolls up cleanly into portfolio and market-level analysis rather than staying siloed at the individual deal level.

Source: Data from CompStak’s proprietary database. Learn more at compstak.com.

Using Lease Comps in Portfolio and Asset-Level Underwriting

Individual lease comps become most useful in due diligence once they are aggregated across a portfolio, because that is where mark-to-market exposure and rollover risk become visible at scale. CompStak’s portfolio comparison of FTSE Nareit Office index landlords against all other office owners shows how this works in practice: Nareit Office tenants pay $62.02/SF in place on average, a 36.9% premium over the $45.31/SF average across all other landlords, and Nareit Office portfolios carry a longer WALT at 69.9 months versus 63.2 months for all other owners, per CompStak’s Portfolio comparison: FTSE Nareit Office index owners vs all other office owners.

Those figures only exist because thousands of individual lease comps were aggregated and weighted by leased square footage, then compared across ownership groups. That is the practical payoff of treating lease comps as more than a single deal record. A due diligence team pulling comps on one building should ask the same question at the portfolio level: how does this rent roll’s WALT and mark-to-market spread compare to the broader market, not just to the last sale comp that closed nearby. Concession structure matters too.

Frequently Asked Questions

What is the difference between a sale comp and a lease comp? A sale comp records the price, cap rate, and terms of a property transaction. A lease comp records the rent, term, and concessions agreed to for a single tenant’s space. Sale comps value the asset; lease comps value the income stream inside it.

Why do underwriters need both sale comps and lease comps? Sale comps establish market value and cap rates from a completed transaction. Lease comps show the rent roll detail, rollover risk, and mark-to-market spread that determine whether the price paid in that transaction is actually supported by durable income.

What is a starting rent in a lease comp? Starting rent is the rent per square foot a tenant pays in the first year of a new lease, before escalations apply. It differs from in-place rent, which reflects whatever rent is currently owed on that lease regardless of lease year.

What is WALT and why does it matter in due diligence? WALT, or weighted average lease term, is the average remaining lease duration across a property or portfolio, weighted by square footage. A short WALT signals more near-term rollover risk and more space that will need to be re-priced against current market rent.

How does CompStak verify sale and lease comps? Comps are contributed through the CompStak Exchange by verified CRE professionals, then screened by machine learning anomaly detection and reviewed by CompStak’s data analyst team before publication. Buyers, sellers, landlords, and tenants are resolved to their actual entities.

What is a True Buyer or True Seller? True Buyer and True Seller are CompStak’s identity-resolved designations for the real investment entity behind a sale transaction, rather than the single-purpose LLC listed on the deed, which lets investors track actual ownership activity across a portfolio.

What is the mark-to-market spread in a lease comp? The mark-to-market spread is the percentage gap between current market rent and a lease’s in-place rent. A positive spread means the tenant is paying below market, which points to embedded rent growth as the lease rolls or renews.

Can lease comps be used without a corresponding sale comp? Yes. Lease comps are useful on their own for market rent studies, appraisal support, and rollover risk analysis. But for acquisition underwriting, pairing lease comps with a sale comp is what connects the rent roll to a defensible market price.

Sale comps and lease comps are two views of the same asset. A due diligence file is only as strong as the weaker of the two. Get started with CompStak to pull analyst-reviewed sale and lease comps for your next deal.