Mass. Gen. Laws ch. 143, § 43: Fire escape affixed by joint owner, lessee or occupant; projection over highway or right of way

Section 43. If a building is owned, leased or occupied, jointly or in severalty, any owner, lessee or occupant may affix to any part of the outside wall of such building any means of egress or of escape from fire specified and described by an inspector, notwithstanding the objection of any other such owner, lessee or occupant; and such means of egress or of escape may project over the highway, or over a right of way for a distance not exceeding one half the width of the right of way.