Oregon law says the assessor must value all property at 100 percent of its real market value. Real market value (RMV) is typically the price your property would sell for in a transaction between a willing buyer and a willing seller on January 1, the assessment date for the tax year. To estimate the RMV for new property, the assessor appraises your property using a physical inspection, local cost data and a comparison of market data from similar types of property. The maximum assessed value is then determined per Oregon statute.  For existing property, the assessor may analyze market data of similar types of property to update the RMV. Some property, such as farm or forest property, may be subject to special valuation processes.

Property is taxed on its assessed value (AV). A property's AV is the lower of its RMV or its maximum assessed value (MAV). Each year, the county assessor determines the property's RMV and calculates its MAV. You are taxed on the lesser of the two, which is called the assessed value (AV).

Residential Appraisal

Residential properties are typically valued using mass appraisal techniques.  Mass appraisal applies the same appraisal principles as an individual appraisal, but applies these principles to groups of properties rather than an individual property.  Valuation tables which include cost factors are used along with market sales data to calculate property values.

Commercial/Industrial Appraisal

Commercial and industrial properties are typically valued using a combination of three established approaches to value: the income approach, the sales comparison approach and the cost approach.  These properties are often valued for assessment purposes using mass-appraisal methods.  These methods can include the use of valuation tables, statistics and adjustments to properties based on verified sales and income data across the county.


Lane County is actively working towards reestablishing a county-wide reappraisal cycle. Reappraisal has been conducted on "hot-spot" areas where the real market values are out of compliance with Department of Revenue standards.  Many areas in the county have not been reappraised since the 1990's, as the result of the implementation of Measure 47/50.  Reappraisal efforts are ongoing each year in residential, commercial, multi-family and industrial neighborhoods.

Sales Data

Property values change from year to year with the real estate market.  It isn't possible to have our appraisal staff visit every property in Lane County each year, so a sales ratio study is performed to determine the direction and amount that property values change within market areas and neighborhoods of the county.

Much of the data used for the ratio study is derived from recent property sales.  The Sales Data Analyst reviews recent sales of property in Lane County trying to determine if the individual sales are representative of fair market or arm's length transactions.  Sales determined to be representative of fair market transactions are used in the assessor's ratio study compiled each year.  The ratio study helps the assessor determine how real market values are moving within individual market areas and neighborhoods in the county.  Using the data from the ratio study, the previous year's certified market values are adjusted to represent 100% of real market value as of January 1 for the upcoming tax year.

Sales data used in the yearly ratio study and the actual ratio reports are available at the self help area located in our lobby.