According to Massachusetts State Law (Chapter 148 Section 26F) all buildings or structures occupied in whole or in part for residential purposes upon the sale or transfer, shall be equipped by the seller with approved smoke detectors/MGL Chapter 148 Section 26F.
An operating smoke detector on every habitable level, including the basement. Finished attic spaces also need smoke detector coverage. In homes with floor space exceeding 1,200 square feet per floor, a second detector will be required.