How do you calculate square footage?

We use the same standards as realtors and appraisers to calculate square footage. This means only the spaces in the plan that are conditioned, or heated, are added to the final calculation. Areas like patios, garages sunrooms, screened porches, and some other bonus areas won’t be included. A basement may be added to the square footage if the space is finished, such as a basement with a bedroom and bathroom.