What Are Real Estate Comps and How Do They Work?

A buyer in Seattle falls for a three-bedroom house listed at $950,000. Her friend says it is overpriced, the seller’s agent says it is a bargain, and the listing site’s automatic estimate lands somewhere in between. Everyone is pointing at “comps,” yet nobody explains what they are or why they disagree. Comparable sales sit behind almost every pricing decision in real estate, from the list price to the appraisal to the final counteroffer. 

This article explains what comps are, how they are selected, which details matter most, how adjustments work, where automated estimates fall short, how buyers and sellers can use them and the mistakes that lead to bad pricing. If you are planning a move, speaking with real estate agents in Seattle Washington early gives you someone who can read these numbers properly.

What Comps Actually Are

Comps, short for comparables, are recently sold homes that resemble the property you are trying to value. The idea is simple: a home is worth roughly what similar homes nearby have recently sold for. Agents use comps to suggest a list price, buyers use them to decide what to offer, and appraisers use them to support a lender’s valuation.

The word that matters most is sold. Active listings show what sellers hope to get, and pending sales show what buyers agreed to pay but have not yet closed. Only closed sales prove what the market actually accepted. Active and pending homes are useful background on competition and direction, but they are not the foundation of a valuation.

How Good Comps Are Chosen

A strong comp matches the subject home on the features that buyers care about most. Appraisers and agents usually look for homes that sold within the last three to six months, which keeps the data current in a market where prices can shift quickly. Distance matters too. In a dense neighbourhood, the best comps may be within a few blocks, while in a rural or unusual area, the search may stretch much further.

Beyond time and place, a good comp is similar in size, age, style, lot, condition and number of bedrooms and bathrooms. Three to five well-chosen comps are generally more useful than a long list of loose matches. In Seattle and the Eastside, small differences in location carry real weight, because school boundaries, views, noise, transit access and even which side of a hill a house sits on can move values noticeably.

Adjustments: Turning Similar Into Equal

No two homes are identical, so comps need adjusting. The logic is straightforward. If a comp has something your home lacks, its sale price is adjusted down to reflect that difference, and if your home has something the comp lacks, the price is adjusted up.

Typical adjustments cover square footage, extra bathrooms, garage spaces, lot size, finished basements, updated kitchens, views and overall condition. The dollar amounts come from market evidence, not guesswork, and they vary by area. A garage may add far more value in a neighbourhood with scarce street parking than in one with wide driveways.

The best comps are the ones needing the fewest and smallest adjustments. If a comp requires large corrections, it is a weaker guide, and the final value should lean more on closer matches.

What Moves a Comp Up or Down in Importance

Some features influence a valuation far more than others, and knowing them helps you judge a comp list.

• Location: Street, neighbourhood and school area usually matter most

• Size and layout: Usable square footage and bedroom count shape buyer demand

• Condition and updates: Renovated homes tend to sell above dated ones, though not dollar for dollar

• Lot and outdoor space: Larger or flatter lots, usable yards and privacy can add value

• Timing: A sale from eight months ago may not reflect today’s market

• Type of sale: Foreclosures, distressed sales and transfers between relatives often do not reflect normal market value and may be set aside

When a comp list ignores these distinctions, the resulting value can be misleading in either direction.

Why Online Estimates Often Miss

Automated valuation tools are convenient, and they can offer a rough starting point. They work by running a formula across public records and recent sales. What they cannot see is the inside of the home. They do not know that the kitchen was remodelled last year, that the roof is near the end of its life or that the house backs onto a busy road.

They also struggle in neighbourhoods with few sales, with unique properties and in fast-moving markets where prices change faster than the data updates. Treat an online estimate as a conversation starter and not a price. A local agent’s comparative market analysis, built from carefully selected sold homes and a visit to the property, is far more reliable.

Using Comps as a Seller

Sellers benefit from comps most when setting the list price. Pricing too high can leave a home sitting while buyers move on, and pricing too low gives away money. Look at what similar homes sold for, how long they took to sell and how close the final price came to the original ask.

Be honest about differences. Your renovated bathroom may be worth something, but so is the neighbour’s larger lot. Ask your agent to explain each adjustment, and compare the sold prices with the active competition. If similar homes are lingering unsold, that is a signal about the ceiling of what buyers will pay.

Using Comps as a Buyer

Buyers can use comps to avoid overpaying and to make stronger offers. Before writing an offer, review recent sales of similar homes and see where the asking price sits. If it is well above the comps, you have grounds to negotiate or to walk away. If it sits below them, expect competition and be ready to move quickly.

Comps also help you prepare for the appraisal. If you offer well above recent comparable sales, the appraiser may value the home lower, leaving a gap you would need to cover. Understanding the comps in advance lets you decide how much risk you are willing to take.

Reading Comps Well: Local Insight and Common Pitfalls

Sankari Realty supports buyers and sellers throughout the Seattle area, with agents who follow neighbourhood sales closely and guide clients from setting a list price through to negotiating at closing. Their day-to-day familiarity with local streets and recent deals helps clients price realistically and respond calmly when the numbers do not match expectations.

Choosing comps takes judgement, and an agent who knows the streets, the buyers and the recent sales can spot a weak comp that a spreadsheet would accept. That judgement matters most in neighbourhoods where homes differ widely from one block to the next. Even so, a few errors show up repeatedly. Relying on listing prices instead of sold prices is one, and using old sales in a market that has moved is another. 

Emotional attachment also gets in the way. Sellers often value their own improvements above what the market will pay, while buyers sometimes anchor on the lowest comp they can find. A balanced look at several good comps, with honest adjustments, produces a more dependable number.

Reading the Numbers With Confidence

Comps are not magic, and they are not a secret reserved for professionals. They are a structured way of asking what similar homes have actually sold for and how your home differs. Once you understand that logic, listing prices, appraisals and offers stop feeling arbitrary. If your search or sale extends north of Seattle, a real estate agent in Bothell can help you apply the same careful comp analysis to homes in that area.