One of the most common questions homebuyers and homeowners ask is: How does an appraiser actually determine what a home is worth?
An appraisal is much more than simply looking at a few recent home sales and averaging the prices. The appraiser analyzes the property itself, the surrounding market and comparable properties to develop an independent opinion of the home’s market value.
I originally put this article together after getting some detailed insight from a local DMV appraiser. While appraisal reporting requirements have evolved over the years, the basic principles behind determining residential property value remain largely the same.
Location Is One of the Most Important Factors
Appraisers generally begin by looking for comparable properties in the same market area as the subject property.
Whenever possible, they look for sales that compete with the subject property from a buyer’s perspective. That may mean properties within the same subdivision, neighborhood or other relevant market area.
If there are not enough appropriate comparable sales nearby, the appraiser may need to expand the geographic area or look further back in time. The important issue is not simply distance or age of the sale, but whether the property is actually a meaningful comparison to the home being appraised.
Recent Comparable Sales Are Important
Appraisals are generally based heavily on actual closed sales because those transactions provide evidence of what buyers have recently been willing to pay for similar properties.
More recent sales are often preferable, but there is not a universal rule that a comparable must have sold within a specific number of months. In some neighborhoods there may be plenty of recent sales. In others, especially areas with unique properties or limited turnover, an appraiser may need to use older sales and analyze changes in the market since those properties sold.
Current listings and pending sales may also provide useful information about market conditions and competition, although closed sales typically provide the strongest evidence of completed transactions.
Comparable Does Not Mean Identical
It is rare to find another property that is exactly the same as the home being appraised.
Appraisers therefore look for properties that are reasonably comparable and analyze relevant differences between those properties and the subject home.
Some of the characteristics an appraiser may consider include:
- Location and neighborhood
- Property type and architectural style
- Living area and overall size
- Lot size and site characteristics
- Number of bedrooms and bathrooms
- Condition and quality of construction
- Renovations and improvements
- Garage, parking and other amenities
- Basements and finished lower-level areas
- Views, location influences and other property characteristics
How Do Appraisal Adjustments Work?
When a comparable property differs from the subject property, the appraiser may make an adjustment to account for a difference that the market recognizes.
One important misconception is that there is a universal dollar amount assigned to a bedroom, bathroom, square foot of living area or particular home improvement.
There isn’t.
The appropriate adjustment should be supported by the market. For example, the value buyers place on an additional bathroom or additional living area can vary considerably depending on the neighborhood, property type, price range and local market conditions.
This is why two homes that appear very similar on paper can still have different market values.
Condition and Renovations Matter — But Not Always Dollar for Dollar
The condition of the property can have a significant impact on an appraisal.
An updated home may compete differently than a similar property that needs substantial renovation. An appraiser may therefore need to account for differences in condition, quality and improvements when comparing properties.
However, homeowners should not assume that spending $50,000 on an improvement automatically increases the appraised value by $50,000. Cost and market value are two different things.
The question is how the market reacts to that improvement and how much buyers are willing to pay for it.
Bedrooms, Bathrooms and Square Footage
Bedroom and bathroom counts are important, but appraisers generally do not simply assign a predetermined amount to each additional room.
The appraiser looks at how those characteristics affect buyer behavior within that particular market.
Living area is handled similarly. A larger home will not necessarily be worth a fixed dollar amount more per square foot. The contributory value of additional living area depends on the property and the market.
Appraisers also distinguish between above-grade living area and finished areas that are partially or completely below grade. A beautifully finished basement can certainly contribute value, but it may not be treated exactly the same as comparable above-grade living space.
Why the Appraised Value May Differ From the Contract Price
When a home is under contract, the appraiser knows the contract price, but the purpose of the appraisal is not simply to confirm that price.
The appraiser must independently analyze the property and available market data and develop a supported opinion of value.
Sometimes the appraisal supports the contract price. Sometimes it comes in higher. And sometimes it comes in lower.
A difference between the contract price and appraised value does not automatically mean that either the buyer, seller or appraiser is wrong. A contract represents what a particular buyer and seller agreed to, while the appraisal is an opinion of market value developed from the available market evidence.
Can a Real Estate Agent Provide Information to the Appraiser?
Yes. A knowledgeable real estate agent can sometimes provide useful factual information about the property or neighborhood.
For example, an agent may know about renovations to the property, recent neighborhood sales or other relevant information that may not be obvious from public records or listing data.
Providing accurate information is different from attempting to pressure an appraiser toward a particular value. The appraiser must remain independent and develop their own opinion of value.
What Happens After the Appraisal Is Completed?
The appraisal may be reviewed as part of the mortgage underwriting process.
Lenders and investors use appraisal review processes and technology to evaluate the report, the comparable properties, adjustments and other information used to support the appraiser’s conclusion.
An appraiser may occasionally be asked to clarify information, correct factual errors or provide additional support for portions of the appraisal.
That review process is another reason the appraiser’s conclusions and adjustments need to be supported by the available market data.
Appraisal Reports Are Changing in 2026
Homebuyers, real estate agents and mortgage professionals will begin seeing a significantly different residential appraisal report.
Fannie Mae and Freddie Mac have introduced the Uniform Appraisal Dataset (UAD) 3.6 and a redesigned Uniform Residential Appraisal Report (URAR). Beginning November 2, 2026, UAD 3.6 becomes mandatory for new appraisal reports submitted through the Uniform Collateral Data Portal for loans subject to these requirements.
The redesigned report is more dynamic and data-driven than the traditional appraisal forms the mortgage industry has used for many years.
What is important for homebuyers to understand is that a different-looking appraisal report does not mean the basic concept of determining market value is disappearing.
Appraisers will still analyze the property, relevant market data, comparable properties and market-supported differences in developing an opinion of value. What is changing substantially is how the appraisal information is collected, structured and presented in the report.
Appraisals Are Based on Market Evidence
Ultimately, an appraisal is a supported professional opinion of market value.
There is no single formula that says a bathroom is worth a certain amount, a finished basement is worth another amount or every additional square foot has the same value.
The appraiser’s job is to analyze how buyers in that particular market respond to those characteristics and use relevant market evidence to support the final opinion of value.
That is also why local market knowledge can be so important, particularly in the Maryland, Washington DC and Northern Virginia markets where neighborhoods, housing styles and property values can change significantly over relatively short distances.
Questions about an appraisal or how the appraisal process affects your mortgage?
Call or text me at 240-670-5090 or email me at CJMT@mainstreethl.com.
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