I’m researching property taxes for Multnomah County as I will probably appeal the values on our new project house. This is what I have found. The Exception below answers what sort of remodeling triggers a new assessment.
Each individual property is taxed on its assessed value. A property’s assessed value is the lower of its real market value or its maximum assessed value. Each year, the county assessor determines the property’s real market value and calculates its maximum assessed value. You are taxed on the lesser of the two, which is called the assessed value. Real market value and maximum assessed value are defined below
Real Market Value (RMV) is the value the assessor has estimated your property would sell for on the open market as of the assessment date. The assessment date for most property for the 2007–2008 tax year is
January 1, 2007.
Maximum Assessed Value (MAV) is the greater of 103 percent of the prior year’s assessed value or 100 percent of the prior year’s MAV. MAV may be increased above3 percent of the prior year’s assessed value if certain changes, defined as exceptions, are made to your property. MAV does not appear on most tax statements.
Exception means a change to property, not including general ongoing maintenance and repair or minor construction. Changes that could affect maximum assessed value include new construction or additions, major remodeling or reconstruction, rezoning with use consistent with the change in zoning, a partition or subdivision, or a disqualification from special assessment or exemption. Minor construction is defined as additions of real property improvements with a real market value that does not exceed $10,000 in one assessment year or $25,000 over a period of five assessment years. Exception value does not appear on your tax statement.