Municipal buildings and public schools may be erected to a height exceeding 35 feet provided that the front, rear and side yards shall each be increased by two feet for each one foot by which such building exceeds 35 feet. Existing municipal buildings which, on May 22, 1995, exceed the height limitations contained in Section 5.02 of these regulations, may be altered or enlarged, provided that the maximum structure does not exceed the maximum elevation of the existing structure and provided further, that any such alteration or enlargement shall comply with all zoning and building requirement