What features are absolutely necessary in order for a room to be appraised as a bedroom is debatable, and somewhat dependent on the age of the home and the individual lender's underwriting guidelines. However, generally acceptable standards are that the room has access to the outside of the home, storage space and a door, and is sufficiently large enough for bedroom furniture.
A bedroom is required to have direct access to the exterior of the home, sufficient natural light, sufficient average ceiling height and ventilation. Basements, converted garages and attics that are being used by the homeowner as bedrooms, may be discounted by the appraiser if those criteria are not met. In addition, windows must be large enough to allow access by a fully equipped firefighter. If there are security bars on a window, there must be a quick-release mechanism for use during emergencies.
Some lenders may allow a partial credit for tandem bedrooms -- a floor design in which you have to walk through one bedroom to get to another. This is considered to be an example of functional obsolescence -- a style that is no longer popular -- and the appraiser may have to adjust the value downward. Similarly, a bedroom located on a level without a bathroom may hurt the value.
A closet does not have to be an architectural feature. It can be a wardrobe that is bought at the local home improvement store and affixed to a bedroom wall. This upgrade tactic is frequently used by investors who are looking to flip properties. They buy a property with a room that was valued as an office, install a wardrobe and list the property for sale. More often than not, the property will appraise for a higher value based on the additional bedroom.
A bedroom is expected to be secure and private, but the meaning of that may be open to interpretation. Some appraisers insist on a door and others don't. In fact, in some open floor plans, the master bedroom never has a door, but it is usually counted as a bedroom. However, a loft above a staircase is not a bedroom --- it has no door and no privacy --- and even though listing agents frequently count it as a bedroom, it will not appraise as one.
The bedroom must be large enough to be considered a sleeping area. The U.S. Department of Housing and Urban Development sets a minimum bedroom area for its government subsidized rental program. The bedroom must be a minimum of 70 square feet and have a minimum horizontal length of 7 feet. It is doubtful that anything smaller than that would appraise as a bedroom since there would be very little room left for a closet.