A bathroom designed for use by the general public must conform to the requirements established by the Americans with Disabilities Act (ADA). For more information, see the Americans with Disabilities Act—ADA Guide for Small Business.
You will want to look at all aspects of your home business operation—parking, doors and entry access, maneuverability inside your house, shelving, and seating. Additionally, you will need to accommodate service animals, such as seeing-eye dogs.