Comparable Sales Analysis: How Appraisers Value Your Home

Comparable Sales Analysis: How Appraisers Value Your Home

When you protest your property taxes in Douglas County, the single most persuasive form of evidence you can present is a well-constructed comparable sales analysis. The Board of Equalization at boe.douglascounty-ne.gov evaluates thousands of protests each year, and the cases that succeed almost always rest on strong comparable data. In 2025, 4,865 protests were filed with a 47% overall success rate — and the median residential reduction was $30,600. Understanding how comparable sales analysis works gives you a significant advantage.

What Is a Comparable Sales Analysis?

A comparable sales analysis (sometimes called a CMA, or comparative market analysis) estimates a property’s market value by examining the sale prices of similar properties that have recently sold nearby. The principle is straightforward: if three homes similar to yours sold for $280,000 to $295,000 in the past year, your home is likely worth somewhere in that range.

This is the same methodology that licensed fee appraisers use when performing a full appraisal for a mortgage lender. It is also the primary method the Douglas County Assessor uses within its mass appraisal system. When you present comparable sales evidence at a BOE hearing, you are speaking the same language the county uses to value your property.

The 8 Key Dimensions of Comparability

Not every sale qualifies as a true comparable. Professional appraisers evaluate potential comps along eight primary dimensions, and you should apply the same framework when building your protest case.

1. Square Footage

Above-grade living area is the most heavily weighted characteristic in residential valuation. Ideally, your comparable sales should be within 15% to 20% of your home’s square footage. A 1,800-square-foot home should be compared to sales in the 1,450 to 2,150 range. Comparisons to homes with dramatically different sizes require large adjustments that weaken the analysis.

2. Lot Size

Lot size matters most in neighborhoods where parcels vary significantly. In a typical Omaha subdivision where lots are uniformly 7,000 to 9,000 square feet, this factor carries less weight. But if your home sits on a quarter-acre lot and you are comparing it to a home on a full acre, the lot size differential must be accounted for. Look for comparables with lots within 25% to 30% of your own.

3. Age / Year Built

The year a home was built affects its value through depreciation, architectural style, and construction standards. A home built in 1965 and a home built in 2005 may be similar in size and location, but they differ in insulation, wiring, plumbing, energy efficiency, and layout preferences. Strong comps are typically within 10 to 15 years of your home’s construction date. When older homes are used as comps, adjustments for effective age and renovation status become critical.

4. Quality Grade

The Assessor assigns a quality grade to every home based on construction materials, architectural detail, and craftsmanship. This grade — sometimes expressed as a letter or numeric code — has a significant impact on assessed value. When selecting comparables, match the quality grade as closely as possible. A “good” quality home should not be compared to an “excellent” quality home without a substantial adjustment. You can find the quality grade for any property on the Assessor’s website.

5. Condition

Condition reflects the current state of repair and maintenance. Two homes with identical blueprints can differ by $40,000 or more if one has a new roof, updated kitchen, and modern HVAC while the other has deferred maintenance. The county rates condition on a scale from poor to excellent. If your home has issues the Assessor has not documented, photographing those conditions and presenting them as evidence at your hearing can be highly effective.

6. Architectural Style

Ranch, split-level, two-story, and bi-level homes appeal to different buyer segments and command different prices per square foot. A 1,600-square-foot ranch typically sells for more per square foot than a 1,600-square-foot split-level in the same neighborhood. When possible, match your home’s architectural style to that of your comparables. When an exact style match is not available, acknowledge the difference and apply a reasonable adjustment.

7. Sale Recency

The more recent a sale, the more relevant it is to your current assessment. Nebraska assessors typically rely on sales from the 24 months preceding the January 1 assessment date. For your protest, prioritize sales from the most recent 12 months. Sales older than 24 months generally carry little weight unless the market has been stable.

When using older sales, you should apply a time adjustment (discussed below) to account for changes in market conditions between the sale date and the assessment date.

8. Proximity / Distance

Location is the foundation of real estate value. The best comparables are in the same neighborhood or subdivision as your property. As you expand the search radius, you introduce variables — school districts, traffic patterns, amenities, neighborhood desirability — that make comparisons less reliable. As a general rule, start with sales within a half-mile radius and expand to one mile only if necessary. Sales from different valuation neighborhoods require careful justification.

Understanding Time-Adjusted Sale Prices

Real estate markets move constantly. A home that sold for $285,000 eighteen months ago may be worth more or less today depending on whether prices have risen or fallen. A time-adjusted sale price accounts for this by applying a market trend factor to the original sale price.

For example, if the market in your area declined by 3% over the past year and a comparable home sold for $300,000 twelve months ago, the time-adjusted price would be approximately $291,000. Conversely, if prices rose 5%, the adjusted figure would be $315,000.

The Douglas County Assessor publishes neighborhood-level sales ratio data that can help you estimate market trends. You can also calculate the trend yourself by comparing the median sale price per square foot in your neighborhood across different time periods. Presenting time-adjusted prices at your BOE hearing demonstrates analytical rigor and makes your evidence more credible.

What Makes a “Good” Comp vs. a “Bad” Comp

A strong comparable sale shares most or all of these characteristics with your property:

The BOE understands that no two properties are identical. Three to five solid comparables that bracket your property’s characteristics are far more persuasive than ten weak comparables that require extensive adjustments.

How to Find and Evaluate Comps Using County Records

Douglas County provides free access to property and sales data through the Assessor’s website. Here is a practical process for building your comparable sales analysis:

1. Pull your own property record. Note your square footage, lot size, year built, quality grade, condition, and style. These are your baseline comparison criteria.
2. Search for recent sales in your neighborhood.Use the Assessor’s sales search tool to find arms-length transactions (exclude foreclosures, estate sales, and family transfers) within the past 12 to 24 months.
3. Filter by similarity. Start with sales that match your home in style and quality grade, then narrow by square footage and age. Aim for at least three to five strong matches.
4. Pull the property record for each comp.Compare the Assessor’s data for the comp to the data for your property. Note any differences in condition, basement finish, garage size, or lot features.
5. Calculate price per square foot.Divide each comparable’s sale price by its above-grade living area. This normalized metric makes it easy to compare properties of different sizes. If your comps sold at $140 to $155 per square foot and the county is assessing your home at $170 per square foot, you have a strong argument for reduction.
6. Apply time adjustments if needed. For sales older than six months, consider whether market conditions have changed and adjust accordingly.

How the BOE Evaluates Comparable Evidence

When you present comparable sales at your hearing, the Board of Equalization considers several factors:

• Relevance— Are the comps truly similar to your property, or do they require so many adjustments that the comparison breaks down?
• Consistency— Do your comps tell a consistent story? If three comps suggest a value of $275,000 to $290,000 and your assessment is $320,000, the pattern is clear. If your comps range from $250,000 to $340,000, the evidence is ambiguous.
• Arms-length transactions— The BOE gives the most weight to sales between unrelated parties at market terms. Distressed sales, relocation buyouts, and intra-family transfers are typically excluded or given less weight.
• Completeness— Did you cherry-pick only the lowest sales, or did you present a balanced view of market activity? Presenting all relevant sales — including those that may not support your case — builds credibility with the Board.

The county may present its own comparable sales. Under the unequal appraisalframework governed by NE Rev. Stat. 77-1502, you can also argue that your property is assessed at a higher ratio of market value than similar properties — an argument that relies on assessed-value-to-sale-price ratios rather than raw comparable sale prices.

Putting It All Together

A well-prepared comparable sales analysis takes time, but it is the most effective tool available to Douglas County homeowners. The 2025 protest datashows that 3,494 residential protests were filed, with a 44% success rate. Homeowners who present organized, data-driven comparable evidence consistently outperform those who rely on general statements about their home’s value.

If you are filing a protest for the first time, review our step-by-step protest guide and our Form 422 filing instructions to understand the full process. The Board of Equalization accepts protests from June 1 through June 30 annually. You can file at boe.douglascounty-ne.gov or call 402-444-6510 for assistance.

Summary

• Comparable sales analysis estimates your home’s value by examining the sale prices of similar nearby properties.
• Evaluate comps across eight dimensions: square footage, lot size, age, quality grade, condition, architectural style, sale recency, and proximity.
• Apply time adjustments to older sales to account for changing market conditions.
• Three to five strong comps are more persuasive than many weak ones. Match your property’s key characteristics as closely as possible.
• Use the Assessor’s website to find sales data and property records for free.
• Present balanced, consistent evidence. Avoid cherry-picking and include context for any adjustments you make.
• The BOE values arms-length transactions, consistency, and analytical rigor.

Let Big Red Value build your comparable sales analysis — we identify the strongest comps for your property, calculate time-adjusted values, and prepare presentation-ready evidence for your BOE hearing.