Up to 50% of the parking spaces required for a theater or other place of primarily evening entertainment, for a church, for multifamily dwelling units, or for a school may be provided and used jointly by banks, offices, certain retail stores, repair shops, service establishments, and similar uses which are not normally open, used, or operated during evening hours (beyond normal business hours of 8:00 a.m. to 5:00 p.m.) if specifically approved by the Board of Supervisors; provided, however, that written agreement assuring the retention for such purpose shall be properly drawn and executed by the parties concerned and approved as to form and execution by the Township Solicitor, and shall be filed and made part of the application for a building permit. Such approval may be rescinded by the Board, and additional parking shall be obtained by the owners, in the event that the Board determines that such joint use is resulting in a public nuisance or otherwise adversely affecting the public health, safety, or welfare.