N.H. Rev. Stat. Ann. § 277:3

Scaffolding or staging more than 14 feet from the ground or floor, swung or suspended from an overhead support or erected with stationary supports, except scaffolding wholly within the interior of a building and covering the entire floor space of any room therein, shall have a safety rail of suitable material properly attached, bolted, braced or otherwise secured, rising at least 34 inches above the floor or main portions of such scaffolding or staging and extending along the entire length of the outside and the ends thereof, with only such openings as may be necessary for the delivery of materials. Such scaffolding or staging shall be so fastened as to prevent it from swaying from the building or structure.