An in-home office is a use specifically designed for the functional needs of the resident of a dwelling wherein the professional services of the practitioner is the salable commodity offered to the client. In-home offices include but are not limited to office of a salesman, sales or manufacturer's representative, office of an accountant, architect, land planner, land surveyor, engineer, attorney, broker, dentist, doctor, psychiatrist, real estate or insurance agent, musician, computer consultant or word processor. The office of a building or renovation contractor is permitted, provided that no other activity relating to the contracting of business, including but not limited to storage of equipment supplies or materials of any kind, is associated with residential lot or in-home office use thereon.