Which space should be included when measuring square footage of a dwelling according to national standards?

When measuring square footage of a dwelling according to national standards, the inclusion of an attached accessory apartment is significant because it is considered a functional part of the living space. An attached accessory apartment is specifically designed for occupancy and typically has its own kitchen and bathroom facilities, making it a usable living area for residents.

National standards for measuring square footage focus on areas that contribute to the overall livable space of the home. Since the attached accessory apartment is integrated into the main dwelling and is meant for residence, it is counted towards the total square footage.

In contrast, while a garage, basement, or porch area may have their uses, they do not qualify as standardized living space. Garages are generally considered utility spaces rather than living areas. Basements may only be counted if they meet specific criteria regarding ceiling height and finish. Porches are also generally not included unless they are fully enclosed and meet livable space standards. Therefore, the inclusion of the attached accessory apartment aligns with national standards for measuring square footage in a residential context.