An ADU (Accessory Dwelling Unit) typically does not count as part of the main home's square footage. Instead, it is considered a separate entity. For instance, if you have a 2,500 square foot house and add a 1,200 square foot ADU, the property is still listed as a 2,500 square foot house with an additional 1,200 square foot ADU. This distinction is crucial for property valuation and compliance with local regulations. While the ADU adds value to the property, it is appraised and marketed separately from the main home's square footage.