Comparable Sales
An 18-month base period is used for property assessment by statute. To take into account any seasonality of sales, the Boulder County Assessor uses 24 months of sales data. If there are not enough sales during that time, up to five years of data can be used for comparison purposes. The official appraisal date is June 30 of the year prior to the reappraisal year. As an example, for the current 2023/2024 tax year, the base appraisal period was July 1, 2020 – June 30, 2022; and June 30, 2022 was the official appraisal date.
Assessment Information
Property information gathered for the valuation process includes ownership, location, use, sales, building and property measurements, construction type and costs, and rental income (if applicable).
The sources include real property deeds and declarations, subdivision maps, building permits, local building contractors, property owners, declarations filed by owners of taxable personal property, and onsite inspections by staff.
A property’s value may increase or decrease as a result of physical changes. Improvements such as new rooms, a finished basement, or extensive remodeling and modernization will increase the value. Paint, a new roof or repairs may not increase the value of a home, but will keep it in good condition so the value does not drop.
