In the world of real estate, price is never a random number pulled out of thin air. Instead, it is the result of a rigorous analysis of comps—short for “comparables.” In real estate terms, comps are recently sold properties in the same geographic area that are similar in size, condition, and features to a property currently being valued. Whether you are a seller trying to set a listing price for your SFH or a buyer trying to decide if an offer is fair, comps are your most valuable resource. They provide the “market evidence” required to justify a price to lenders, appraisers, and the IRS. Without accurate comps, a property might stay on the market for months or, conversely, sell for far less than its true value.
For an investor looking at a specific parcel, comps are the heartbeat of the deal. They allow you to project the “After Repair Value” (ARV) and determine if the investment makes sense. When a property is under contract, the lender’s underwriter will spend a significant amount of time reviewing the comps to ensure the bank isn’t over-lending. If the comps don’t support the purchase price on the PSA in real estate, the deal could fall apart before it ever reaches the final settlement statement.
The Criteria for a Perfect Comp
Not every house that sold down the street is a valid comp. To ensure accuracy, real estate professionals look for properties that meet strict criteria. The closer the match, the more reliable the valuation. A “perfect” comp generally meets the following standards:
- Location: Ideally, comps should be within a half-mile radius of the subject property and within the same school district or neighborhood boundaries.
- Recency: The property must have sold recently—typically within the last three to six months. In a fast-moving MSA, a sale from a year ago is considered “stale” and irrelevant.
- Size and Layout: The square footage should be within 10-20% of the subject property, and the bed/bath count should be identical if possible.
- Condition: A fully renovated home is not a comp for a “fixer-upper” with a latent defect in the foundation.
How Appraisers Use Comps vs. Real Estate Agents
While both agents and appraisers use comps, they do so with different goals. A real estate agent creates a Comparative Market Analysis (CMA) to help a seller win the “beauty contest” of the open market. They might look at “active” and “pending” listings to see the competition. An appraiser, however, only cares about “sold” data. Their job is to provide a conservative valuation for the lender as part of the TRID compliance process. They will take the three best sold comps and apply “adjustments.” For example, if Comp A has a three-car garage and the subject property only has two, the appraiser will subtract value from Comp A to make it “match” the subject property. This ensures the final settlement statement reflects the true appraised value.
Comps in the Commercial and Development Sector
In the commercial world, comps are more complex. If you are practicing plottage in real estate, you aren’t just looking at the price of single lots; you are looking at the price per square foot of “developable land.” Investors will look at the net absorption of office or retail space in the MSA to determine if the comps justify a new build. They will also analyze a T12 in real estate of similar buildings to see if the “Cap Rate” is consistent with the market. For a developer, a comp isn’t just a house; it’s a proof of concept that their project will be profitable.
The Danger of “Bad” Comps
Using improper comps can lead to financial disaster. If a seller uses a “outlier” (a house that sold for way too much due to a sentimental buyer) as their primary comp, they will overprice their home and it will sit vacant. For a buyer, using bad comps might lead them to offer more than the bank is willing to lend. This creates a “gap” that the buyer must cover with cash, requiring a new POF (Proof of Funds) to show the lender they can afford the difference. Always ensure your comps account for “distressed sales” (like a foreclosure), as these can artificially drag down the value of a parcel.
Conclusion: Data-Driven Decisions
Comps are the foundation of every smart real estate decision. They remove the emotion from the transaction and replace it with hard data. Whether you are buying your first SFH or managing a portfolio of commercial parcels, you must become an expert at reading and interpreting comp data. It is the only way to ensure you are getting a fair deal.
Before you go under contract, ask your agent for a detailed CMA. Look for any latent defect in the comp properties that might make them an unfair comparison. If you are an investor, cross-reference the comps with the T12 to see if the income supports the valuation. Finally, check your settlement statement to ensure the final sale price is recorded accurately—because one day, your home will become the “comp” for your neighbor.
