What is Assessed Value vs Market Value?
Assessed value is the dollar amount assigned to a property by the county appraisal district for the purpose of calculating property taxes. Market value (or fair market value) is the price a property would sell for on the open market between a willing buyer and a willing seller. These two numbers are related but often different, and understanding the distinction is important for investors analyzing deals, estimating holding costs, and evaluating whether a property's tax burden is accurate.
In Texas, the law requires that assessed value equal 100% of market value. In practice, appraisal districts often assess properties below their true market value because they rely on mass appraisal techniques, use data that's months or years old, and process too many properties to give each one individual attention. Conversely, in rapidly appreciating markets, assessed values can sometimes exceed what the property would actually sell for -- particularly after aggressive reassessments following a boom.
How assessed value is determined
County appraisal districts use three approaches to determine assessed value, similar to the methods used by licensed appraisers. The sales comparison approach examines recent sale prices of comparable properties in the area. The cost approach calculates the cost to rebuild the structure from scratch, minus depreciation, plus land value. The income approach (used primarily for commercial and rental properties) capitalizes the property's income stream to derive a value.
For residential properties, the sales comparison approach is the primary method. The appraisal district identifies recent sales of similar homes in the area and uses those as the basis for the assessed value. Because they're valuing hundreds of thousands of properties simultaneously, the analysis is less precise than a licensed appraiser's individual property valuation. This creates opportunities for protest when the mass appraisal doesn't accurately reflect a specific property's condition, features, or market position.
Why assessed value and market value differ
Several factors cause assessed value to diverge from actual market value. Assessment lag is the most common -- appraisal districts value properties as of January 1 each year, using sales data from the prior year. In a market that's appreciating at 8-10% annually, the assessed value can be significantly below the current market value. Conversely, in a declining market, assessments may be higher than what the property would actually sell for.
Property condition is another major factor. The appraisal district typically doesn't inspect the interior of homes. A property that has been extensively renovated may be assessed far below its true value because the improvements aren't reflected in the records. On the other hand, a property in poor condition may be assessed as if it's in average condition because the district doesn't know about deferred maintenance or damage.
Exemptions also create a gap between assessed value and taxable value. In Texas, homestead exemptions, over-65 exemptions, disability exemptions, and the 10% annual appraisal cap for homesteads can significantly reduce the taxable value below the assessed value. When an investor purchases a homesteaded property, these exemptions disappear, and the property tax bill can increase substantially.
Using assessed value in deal analysis
Assessed value is useful as a data point but should never be used as a substitute for a proper comp analysis or ARV estimate. Some investors use the assessed value as a rough floor for property value -- if the county says the property is worth $180,000, it's probably not worth less than $150,000 unless there are significant condition issues. But relying on assessed value for pricing decisions is a mistake because it can be significantly off in either direction.
Where assessed value is most useful is in estimating ongoing property tax obligations. Once you know the assessed value and the local tax rate, you can calculate the annual property tax, which feeds into your cash flow analysis for rentals and your holding cost estimate for flips. Just remember to account for exemption changes -- if the seller has a homestead exemption that you won't qualify for as an investor, the tax bill will increase after closing.
Protesting assessed value
Investors should protest property tax assessments annually for every property they own. The protest process involves presenting evidence that the assessed value exceeds the true market value. Evidence can include recent comparable sales at lower prices, an independent appraisal, photos documenting property condition issues, or evidence that the district used incorrect property characteristics (wrong square footage, wrong year built, etc.).