This workshop will review the characteristics that determine construction quality for residential properties by use of the Marshall & Swift Valuation Service. House images will be included in the presentation and will lead to extensive classroom participation. Actual construction costs will also be considered as a guide to determining quality. Images will also assist in the discussion on rating homes for condition in relationship to the definition and description for each condition rating. The determination of condition will lead directly into calculations for effective age. Effective age will be defined and demonstrated on how to extract it from the market. Several data sets will be provided for the students to calculate effective age and how to use for the development of a depreciation or percent good table. Topics discussed are: USPAP review, cost approach, quality, condition, physical deterioration using effective age, functional obsolescence, external obsolescence and depreciation and effective age extraction.