Patios, terraces, boardwalks, basketball courts, at-grade decks, and tennis courts. These improvements may be built at any size within the permitted building envelope. Outside the permitted building envelope, these improvements may not be greater than 250 square feet. However, any lot with a frontage of less than 50 feet shall be exempt from this section on the condition that there be a minimum side yard setback of two feet to the property line and rear yard setback of 10 feet to the property line and the total impervious coverage of the rear yard shall not exceed 250 feet outside the permitted building envelope. For lots with a road frontage of 50 feet or greater, a minimum setback of 10 feet shall be maintained from all property lines, and the total impervious coverage of the rear yard shall not exceed 250 feet outside the permitted building envelope. A zoning permit shall be required and a construction permit may be required.