Mass Appraisal

Fee appraisers and the Assessor’s office have different purposes and methods for valuing property.  A fee appraiser will value property for financing and other purposes. In this case you will typically receive an appraisal consisting of three sales that are indicative of the market value of the subject property.  These sales are within close proximity to the subject property, share similar design, size, age, garage type and size as well as basement type and size.  These sales occur within a time frame of 1 to 3 months of the date of appraisal.  The fee appraiser will make adjustments to these sales based on similarities and differences which will result in an indicated market value as of the specified date.

The Assessor’s office values your property for taxation purposes. Methods used by a fee appraiser are not appropriate for the Assessor’s office  due to time constraints for the number of properties that have to be valued, the number of sales that are used and the resources available.  State statute minimum requirement for sales gathering is 18 months, and depending on the number of sales available for the property type, a maximum of 5 years. Douglas County utilizes 24 months of sales for Residential and vacant land parcels.

Because the market can change gradually or dramatically during that time frame, the law requires that before any values can be calculated, the sales have to be analyzed and adjusted to one point in time which is  June 30th of each even numbered year prior to the reappraisal.

After the sales are adjusted for time a technique called Multiple Regression Analysis (MRA) is used to determine market value. MRA is appropriate for mass appraisal purposes because it is essentially an automated application of the sales comparison approach that uses all similar property type sales in geographic areas, not just three. MRA determines the proper adjustment for property characteristics that are important to the market. This is done through an algorithm designed to fit the sale prices as closely as possible. The sales are separated by property types (Single family, Condos, Townhomes) and regional location (economic areas).  Value models are developed for each property type and their respective economic area. The property characteristics included in the value models are design type, quality, living area size, age, bath type and count, garage type and size, basement type and size, heating type, as well as the neighborhood location. Some characteristics have been collected but are not adjusted such as bedroom count because other features such as total living area and quality type account for it.