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King County Department of Assessments

Fair, Equitable, and Understandable Property Valuations

Department of Assessments

500 Fourth Avenue,
Suite ADM-AS-0708,
Seattle, WA 98104

Office Hours:
Mon - Fri
8:30 a.m. to 4:30 p.m.

TEL: 206-296-7300
FAX: 206-296-5107
TTY: 206-296-7888

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Glossary of terms for residential parcels

ABOVE GRADE LIVING AREA; AGLA
The living area in a house not including the basement.

ACCESSORY IMPROVEMENTS
Improvements other than the principal buildings.

AD VALOREM TAX
A tax levied in proportion to the value of the thing(s) being taxed. Exclusive of exemptions, use-value assessment provisions, and the like, the property tax is an ad valorem tax.

AD VALOREM
According to value.

ADJUSTMENTS
Modifications in the reported value of a variable, such as sale price. For example, adjustments can be used to estimate market value in the sales comparison approach by modifications for differences between comparable and subject properties.

APPRAISAL DATE
The date as of which a property's value is estimated.

APPRAISAL RATIO STUDY
A ratio study using independent appraisals as indicators of market value.

APPRAISAL RATIO
(1) The ratio of the appraised value to an indicator of market value. (2) By extension, an estimated fractional relationship between the appraisals and market values of a group of properties.

APPRAISAL REPORT
The oral or written communication of a completed appraisal.

APPRAISAL STANDARDS BOARD
The division of the APPRAISAL FOUNDATION that develops, publishes, interprets, and amends the Uniform Standards of Professional Appraisal Practice on behalf of appraisers and users of appraisal services.

APPRAISAL
(1) The act of estimating the money value of property. (2) the money value of property as estimated by an appraiser. (3) Of or pertaining to appraising and related functions, for example, appraisal practice, appraisal services. Compare assessment.

APPRAISAL-SALE PRICE RATIO
The ratio of the appraised value to the sale price (or adjusted sale price) of a property; a simple indication of appraisal accuracy.

APPRAISER
One who estimates the value of property; more commonly, one of a group of professionally skilled persons holding themselves out as experts in valuation.

AREA
A geographic area defined and named by the Department of Assessments. These areas typically encompass properties within a group of neighborhoods that are more or less equally subject to economic forces that largely determine the value of the properties in question.

ASSESSED VALUE
A value set on real estate and personal property by a government as a basis for levying taxes.

ASSESSMENT EQUITY
The degree to which assessments bear a consistent relationship to market value.

ASSESSMENT LEVEL
The common or overall ratio of assessed values to market values.

ASSESSMENT PROGRESSIVITY
An appraisal bias such that high-value properties are appraised higher than low-value properties in relation to market values.

ASSESSMENT RATIO
(1) The fractional relationship an assessed value bears to the market value of the property in question. (2) By extension, the fractional relationship the total of the assessment roll bears to the total market value of all taxable property in a jurisdiction. See level of assessment.

ASSESSMENT REGRESSIVITY
An appraisal bias such that high-value properties are appraised lower than low-value properties in relation to market values.

ASSESSMENT
(verb) The official act of discovering, listing, and appraising property. (noun) The value placed on property in the course of such act.

ASSESSMENT-SALE PRICE RATIO
The ratio of the assessed value to the sale price (or adjusted sale price) of a property.

AVERAGE DEVIATION
The arithmetic mean of the absolute deviations of a set of numbers from a measure of central tendency, such as the median. Taking absolute values is generally understood without being stated. The average of the numbers 4,6, and 10 about their median (6) is (2+0+4)/3 =2. The average deviation is used in computing the coefficient of dispersion.