When real estate appraisers and real estate measure homes, they usually adhere to what is known as the ANSI Standard. In North Carolina, the Real Estate Commission developed what has become known as the "Yellow Book". These guidelines that were developed by the Commission, basically mirror the ANSI guidelines.
Some quick facts on how to measure a home, and what is included in the finished heated, living areas:
1. A home must be heated by a fixed system. This includes, but is not limited to: forced/ducted systems, radiant or solar heat, that is permantly attached to the dwelling. A portable heater is not considered as a coventional heating system.
A property does not have to have a A/C system.
2. A home should be finihsed with similar materials that are accepted by the market.
3. The ceiling height should be of atleast seven feet. Some exceptions apply.
4. For a room to be considered as living area, it has to be directly accessible through other heated, and finished living areas. For example, a room cannot be counted as a living area if it can only be accessed through the garage.
5. Any area that is below grade, cannot be counted as "above grade living area", no matter how good the quality of the finish is.
This does not mean that the area below grade is worth less than the area above grade. In some homes, the quality of constrcution is equal to, or better than the above grade living area. Although in some homes, mainly older homes, the quality is inferior with such items such as veneer panel walls, and drop ceilings.
So why does my square footage differ from the plans when purchased new, or the county tax records?
On average, the home will grow from when it is compared to the plan square footage. The appraiser or real estate agent should measure the home from the exterior, at the FACE OF THE WALL, not from the vertical trim pieces. While the county tax accessor does measure each and every home, they do round the numbers a little differantly than appraisers, and they have to measure every home in an entire city, so mistakes are bound to happen.
The American National Standards Institute (ANSI) adopted a standard for measuring single-family residences. This standard is known as Z765. This standard is reconized by architects, various state boards, Fannie Mae, and HUD/FHA.