The House Detective by Barry Stone, Certified Home Inspector
Dear Barry: We just learned that the county tax assessor is counting our basement as an additional bedroom. This increases the appraised value of our home and requires us to pay higher taxes. We’ve never regarded the basement as a legal bedroom because the window is very small and the sill is more than five feet above the floor. Also, the basement has no clothes closet, as one would expect in a bedroom. What are the applicable requirements that would qualify our basement as a legal bedroom? Leslie
Dear Leslie: Your basement does not qualify as a bedroom unless it has window dimensions that meet a list of particular requirements. These standards can vary in their specifics, depending on which building code is used in your area, but the general intent is the same regardless of the code that is in force. Basically, bedroom windows must be large enough and low enough to enable emergency escape, and the window size must meet minimum standards to privide natural light and adequate ventilation.
For emergency escape, the following standards apply: The openable portion of a bedroom window must have a minimum dimension of 5.7 square feet, unless the sill is lower than the outside grade level. In that case, the overall dimension must be at least 9 square feet. The width of window openings must be no less than 24 inches and the height no less than 20 inches. If the windowsill in a basement bedroom is lower than the outside grade level, there must be an exterior window well that meets an additional list of minimum size requirements.
Windowsills in any bedroom must be no higher than 44 inches above the floor, although lower sills were often allowed in older homes. In a basement bedroom, sill heights can exceed 44 inches if there is a permanently installed ladder or stairway to the window opening.
As a source for natural light, the area of the window, according to the Uniform Building Code (UBC), must be no less than one-tenth of the room’s floor area. In municipalities subject to the International Residential Code (IRC), this requirement is only 8% of the floor area.
As a source of exterior ventilation, the UBC requires the area of the window opening to be no less than one-twentieth of the room’s floor area. According to the IRC, only 4% of the floor area is required.
As for storage, there is a common belief that closets are required in bedrooms. The fact is, no such standards can be found in any of the building codes. Closets are included in the construction of homes as a standard of practice, not as a legal requirement.
If you believe that your home has been incorrectly evaluated by your local tax assessor, you can request a review of their assessment. If they are unwilling to cooperate, you can complain, in person, to your local elected representative (i.e. city counsel-person or county supervisor).