Private clubs or lodges serving food and beverages with use being restricted to members and their guests. Adequate dining room, kitchen and bar space must be provided according to standards imposed upon similar unrestricted customer operations. The serving of alcoholic beverages to members and their guests shall be allowed, provided that such service is in compliance with applicable federal, state and municipal regulations. Offices of such use shall be limited to no more than 20% of the gross floor area of the building.