The terms and provisions of this chapter shall not be made applicable to a building or premises or portion thereof, the principal use of which is for the practice of medicine or dentistry or similar type of medical professional personal services, the practice of law, financial institutions or the operation of general office activities; provided, however, such activities shall be subject to the terms and provisions of this chapter when accessory to the operation of commercial establishments as herein defined. The terms and provisions of this chapter shall not be made applicable to any activity carried on or operated by a governmental institution or jurisdiction or by any eleemosynary institution, organization, person or owner. (1976 Code § 31.08)