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Property Assessment

Information on how property is assessed

Your property assessment

Property is taxed on its Assessed Value. A property's Assessed Value (AV) is the lower of its Real Market Value (RMV) or its maximum Assessed Value (MAV). Each year, the County Assessor determines the property's RMV and calculates its MAV.

Real Market Value (RMV)

Oregon law says the Assessor must value all property at 100 percent of its RMV. 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 your property, your county assessor appraises your property by comparing sales of similar properties, building costs and net operating income if applicable. Some property, such as farm or forest property, may be subject to special valuation processes.

Maximum Assessed Value (MAV)

A property's Maximum Assessed Value (MAV) is the taxable value limit established for each property. The first MAV for each property was set in the 1997-98 tax year. For that year, the MAV was the property's 1995-96 RMV minus 10 percent. For example, if a residential property had a RMV of $100,000 for the 1995-96 tax year, its 1997-98 MAV would have been $90,000. MAV can increase for only two reasons.

1. Three Percent Increase

For tax years after 1997-98, MAV is derived as the greater of the prior year's MAV or the prior year's Assessed Value increased by three (3) percent. For the majority of Washington County accounts, the MAV will increase 3 percent per year.

2. Exceptions

  • Changes in the property value as the result of new property or new improvements to property. These property events from minor construction will generally increase RMV, although they may not change MAV,
  • The property is partitioned or subdivided,
  • The property is rezoned and the use is changed consistent with rezoning,
  • The property was omitted from previous tax rolls, or
  • The property becomes disqualified from exemption, partial exemption or special assessment.

New construction affects MAV if it increases the value of the property by more than $18,200 in any one year or $45,000 within any consecutive five years.

Property Tax Basics Video: Why did my taxes go up more than 3%? 

Learn more about why property taxes may have increased more than 3% and how Property taxes are calculated. This video explains several factors that may have caused the increase.

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