Appraisal Basics
How Are Comparable Sales Selected?
The comparable-sales process is the backbone of a credible opinion of value — here's how it actually works.
"Comparable sales" get mentioned constantly in appraisal and tax-appeal conversations, but the actual selection process is more disciplined than most people expect. It isn't just picking a few nearby homes that sold recently — it's a structured research and adjustment process designed to isolate what your specific property is actually worth.
What Makes a Sale "Comparable"
A true comparable sale needs to satisfy several criteria at once — not just proximity to your property:
Location
Same neighborhood or a genuinely comparable one — proximity alone isn't enough if market conditions differ meaningfully.
Sale Recency
Sales closer to the effective date of value are generally more reliable, especially in a fast-moving market.
Size & Style
Similar gross living area, bedroom/bathroom count, and architectural style reduce the number of adjustments needed.
Age & Condition
A recently renovated comp and an original-condition subject property require careful adjustment to compare fairly.
Arm's-Length Transaction
Sales between related parties, foreclosures, or distressed sales are scrutinized or excluded unless properly adjusted for.
The Adjustment Process
No two homes are identical, so once comparables are selected, the appraiser adjusts each one's sale price up or down to account for meaningful differences from your property — adding value for features the comp lacks that your property has, and subtracting for features your property lacks that the comp has.
Why This Matters for a Tax Appeal
A Board of Equalization hearing is fundamentally a comparison of evidence: the county's mass-appraisal basis against whatever you present. A well-documented, properly adjusted comparable-sales analysis gives the board something concrete and verifiable to weigh — far more persuasive than simply asserting a value feels too high. It's also why appraisers can't simply use whichever sales happen to support the lowest number: the analysis has to be independently defensible, or it won't hold up to scrutiny at the hearing.
Two Things That Surprise Most Homeowners
Similarity usually beats proximity
It's tempting to assume the house next door is automatically the best comparable. But a nearly identical home two streets over — same size, age, condition, and design — is often more reliable market evidence than the house directly next door if that neighbor's home is a different style, square footage, or renovation level. Distance is only one of several factors an appraiser weighs; it doesn't override genuine dissimilarity.
What a renovation cost isn't what it adds in value
Adjustments are derived from what the market actually pays for a given difference — not from what it cost to build. A $40,000 kitchen renovation doesn't automatically add $40,000 to a home's value; it adds whatever amount comparable sales evidence shows buyers in that market are actually paying for a similar upgrade, which can be more, less, or occasionally close to the original cost.
Frequently Asked Questions
This information is provided for general educational purposes about the appraisal process and is not legal or tax advice. Comparable selection and adjustment practices follow professional appraisal standards and may vary by assignment — see the Georgia Department of Revenue for property tax appeal specifics.
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Last reviewed: August 2026