Residential Appraisal

The Residential Appraisal Division is responsible for assessing residential zoned properties and manufactured homes in mobile home parks in Snohomish County.

Mass Appraisal Process

The county uses a "mass appraisal" process to appraise the more than 254,000 residential properties each year. "Mass appraisal" is the processes of valuing large numbers of properties as of a given date, using standard methods, employing common data, and allowing for statistical testing. Standard procedures are used to collect property data, analyze data, apply the results of the analysis, and report the results.

Computer programs apply market derived land rates by neighborhood and property type. Computer programs apply building costs and depreciation factors calibrated to local market conditions using sales data, by neighborhood, building style, grade of construction, and building condition. View yearly reports of how this process was administered.


The following resources are available to assist you in understanding property taxes and property tax assessments: