Par. 1. - Every building hereafter erected more than seventy-five feet in height, or hereafter increased in height to more than seventy-five feet, shall be a first class building. Every second class building hereafter erected more than four stories in height, and any second class building now in existence and increased in height to more than four stories shall have the first floor and the basement and cellar stories of first class construction except as hereinafter otherwise mentioned for buildings for habitation. Every building for habitation hereafter erected covering more than five thousand square feet, or more than five stories in height, shall be a first class building. Every building altered or enlarged and occupied or to be occupied as a habitation, to be in excess of sixty-five feet in height, or in excess of five thousand square feet in superficial area, or in excess of five stories in height, shall be a first class building. Every building hereafter erected within the building limits to be occupied as a permanent schoolhouse shall be a first class building. Every building hereafter erected as a theatre, and every building hereafter altered to be occupied as a theatre, shall be a first class building. Every building hereafter erected for, altered to or converted to use as a moving picture house shall be a first class building. All other buildings may be of second or third class construction.

Par. 2. - Except as is otherwise provided herein, buildings adapted for habitations, and not more than five stories in height, may be erected, remodelled or enlarged of second class construction, but no such building shall exceed five thousand square feet in superficial area or sixty-five feet in height. Every such building exceeding thirty-five hundred square feet of superficial area, and every such building exceeding seventeen hundred and fifty square feet in superficial area, and more than four stories or fifty-five feet in height, shall have the first floor and basement and cellar stories of first class construction, with no openings through the first floor, except for piping; provided that stairways from the first story to the outside may penetrate the floor construction. Said stairs herein referred to are to be fireproof, separated from the basement or cellar by walls of solid masonry at least eight inches thick, with no opening to cellar or basement. The first story, or basement, or both the first story and basement, in such building more than seventeen hundred and fifty square feet in superficial area so constructed, remodelled or enlarged, may be used for mercantile purposes; provided that the floors and walls separating the portion of the building used for mercantile purposes and the portion used for habitation be of first class construction with no openings, except for piping, but that stairways from the portion used for habitation to the outside may penetrate the mercantile portion. In such event, the stairs herein referred to are to be constructed of incombustible material and separated from the latter by solid masonry walls at least eight inches thick with no opening to the portion used for habitation. In such buildings where the second floor is of first class construction the requirement providing for the first floor, basement and cellar stories to be of first class construction may be omitted.

[1921, c. 289, sect. 2.]

Restriction of Areas

Par. 3. - ■ Any first class building used above the first floor as a warehouse or store for the storage or sale of merchandise shall have all vertical openings protected by fireproof enclosures. Such enclosures shall, if enclosing stairs or escalators, have automatic doors, and all glass in the enclosure shall be wire glass.

Par. 4. - Such a building shall be so divided by brick walls built like party walls with the same openings allowed, that no space inside the buildings shall exceed in area ten thousand square feet, except that when any such building has a frontage of not less than fifty feet on each of two streets, such space may exceed ten thousand square feet in area, provided that buildings in which such extension of area beyond ten thousand square feet is permitted shall have automatic fire sprinklers installed and means of ingress and egress satisfactory to the commissioner and the board of appeal.

Par. 5. - Second class buildings used above the first floor as warehouses or stores for the storage or sale of merchandise shall be so divided by brick walls, built like party walls with the same openings allowed, that no space inside such buildings shall exceed in area ten thousand square feet, and no existing wall in any second class building shall be removed so as to leave an area of more than ten thousand square feet, nor shall any existing wall separating areas which combined would exceed ten thousand square feet in area, have openings cut in it greater in area or number than is allowed in this act for party walls.

Par. 6. - Every second class building more than three stories high and used above the first floor as a warehouse or store for the storage or sale of merchandise, shall have all vertical openings for elevators and stairways, air or light shafts, through its floors protected by fireproof enclosures. Such enclosures shall be supported by fireproof supports and framing, and shall, if enclosing stairs or escalators, have automatic doors, and all glass in the enclosure shall be wire glass.

Par. 7. - No building used above the first floor for the storage or sale of merchandise shall have less than two means of egress from every story, one of which means may be either an outside fire escape or through a brick wall closed by automatic doors into a building of the same class; except that an independent monumental stairway extending from the basement to the second floor may be constructed.

Buildings for Manufacturing Purposes

Par. 8. - Buildings outside the building limits and adapted exclusively for manufacturing, storage, mechanical or stable purposes, may be built under such conditions as the commissioner shall prescribe. If of wood such buildings shall not exceed forty-five feet in height.

[1914, c. 782, sect. 4.]

[1916, c. 248, Special Act.]

[1918, c. 179, sect. 7, Special Act.]

[1921, c. 289, sect. 2.]