Buildings occupied in whole or in part as defined in this code shall comply with the requirements hereinafter set forth concerning occupancy, size, light and ventilation in order to provide a safe and healthful environment.
A. 
Calculation. For the purposes of this regulation, each person 12 years of age and older shall be counted as one person. Children more than one year old but less than 12 years old shall be deemed to be 1/2 person, and infants up to one year old shall not be counted. The floor area shall be based upon the area of habitable rooms contained within the living unit, exclusive of utility and storage rooms, halls, closets, porches and any connecting spaces. Any area in a habitable room which has a ceiling height of less than five feet shall not be counted or included in the computation of the space.
B. 
Dwelling units.
(1) 
Every dwelling unit shall have at least 120 square feet of habitable floor space for the first occupant, plus 70 square feet of habitable floor space for each additional occupant. Each dwelling unit shall contain one habitable room with at least 120 square feet of floor area and a minimum horizontal dimension of eight feet. Any additional habitable rooms shall have a minimum floor area of 70 square feet and a minimum horizontal dimension of seven feet.
(2) 
Mixed occupancies; apartments. All new dwelling units subject to §§ 250-18F and 250-19E shall have 400 square feet of habitable space for each efficiency or one-bedroom (sleeping room) apartment, and each additional sleeping room shall have 100 square feet of habitable space.
[Added 3-8-1979 by L.L. No. 4-1979]
C. 
Sleeping rooms. No room in any dwelling unit or rooming unit shall be used for sleeping purposes unless there is a minimum habitable floor space of 70 square feet for the first occupant and minimum habitable floor space of 50 square feet for each additional occupant.
D. 
Ceiling height. At least 1/2 of the floor space of any habitable room must have an average ceiling height of at least seven feet six inches. Portions of floor spaces having ceiling heights less than five feet shall not be counted.
A. 
It shall be prohibited to use for sleeping purposes any kitchen, nonhabitable space or public space.
B. 
It shall be prohibited to use any cellar space as habitable space.
C. 
Use of single-family dwelling by more than one family is prohibited.
D. 
Use of a two-family dwelling by more than two families is prohibited.
A. 
Basements or cellars. The basement or cellar of any building shall be dry and ventilated and shall be kept free from rubbish accumulation and infestation.
B. 
Basement dwelling units. No room in any basement shall be occupied as a habitable room unless:
(1) 
The finished floor surface is not more than four feet below grade.
(2) 
The ceiling is not less than four feet above grade.
(3) 
The floors and walls are waterproof and damp-proof in accordance with an approved method, if in contact with earth.
(4) 
Such waterproofing shall be between the floor or wall finish and the ground.
C. 
Lighting and ventilation. Every habitable room in a dwelling or dwelling unit shall contain a window or windows opening directly to the outside air, and the total area of said window or windows shall not be less than 10% of the floor area of such rooms, provided that such window shall not be less than 10 square feet. All window sash shall be glazed and provided with suitable hardware, and shall be made to open to the extent of not less than 5% of the floor area of such room.
A. 
Height. Public space shall have a minimum height of seven feet six inches measured from finished floor to finished ceiling.
B. 
Light. Public spaces shall be provided with artificial light. In public stairs, stairways and passageways, artificial light shall be electric lighting available at all times so as to afford safe passage for occupants and users. Such lighting shall conform to the following:
(1) 
A sufficient number of fixtures shall be provided so that the distance between fixtures is not more than 30 feet, and so that no wall is more than 15 feet distant from a fixture.
(2) 
Incandescent lighting shall be based on not less than 1/4 watt per square foot of floor area, except that each fixture shall have a lamp or lamps with a total of not less than 25 watts.
(3) 
Fluorescent lighting shall be based on not less than 1/10 watt per square foot of floor area, except that each fixture shall have a lamp or lamps of a total of not less than 15 watts.
(4) 
Where under these formulas the calculated wattage does not correspond to that of a standard lamp, the next larger size shall be used.
C. 
Ventilation. Public spaces shall be provided with either natural ventilation, conforming to the requirements for habitable space, or with mechanical ventilation.
A. 
Height. Nonhabitable space, except crawl spaces and attics, in multiple dwellings shall have a minimum height of seven feet, measured from floor to ceiling.
B. 
Toilet rooms and bathrooms.
(1) 
Toilet rooms and bathrooms in one- and two-family dwellings shall have provisions for privacy.
(2) 
Toilet rooms and bathrooms for dwelling units in multiple dwellings shall be located within the dwelling units and shall be accessible from any sleeping room without passing through any other sleeping room.
(3) 
Unless located within dwelling units or directly connected with sleeping rooms, toilet rooms and bathrooms in multiple dwellings shall be provided in each story containing habitable space and shall be accessible thereto.
(4) 
Toilet rooms for employees in multiple dwellings shall be in separate rooms for each sex where there are five or more employees, shall be readily accessible to such employees and shall not open directly into any public kitchen or other public space used for the cooking or preparation of food.
(5) 
In one- and two-family dwellings, bathrooms and toilet rooms shall be provided with floors of moisture-resistant material.
(6) 
In multiple dwellings, floors of bathrooms, toilet rooms and similar spaces shall be waterproof; such waterproofing shall extend six inches or more above floors, except at doors, so that floor can be flushed or washed without leaking.
C. 
Light.
(1) 
Kitchenettes, bathrooms and toilet rooms shall be provided with artificial light appropriate for the use of such rooms.
(2) 
Laundry rooms, furnace rooms and similar nonhabitable space shall be provided with artificial light appropriate for the intended use of such rooms.
(3) 
Stairs shall be provided with artificial light to allow safe ascent or descent.
D. 
Ventilation.
(1) 
Kitchenettes, bathrooms and toilet rooms shall be provided with ventilation in accordance with either of the following:
(a) 
Natural ventilation as required for habitable space, except that such openable areas shall not be less than one and 1/2 square feet for bathrooms or toilet rooms and not less than three square feet for kitchenettes; or
(b) 
Mechanical ventilation exhausting not less than 25 cubic feet per minute for bathrooms and toilet rooms and not less than 100 cubic feet per minute for kitchenettes.
(2) 
Spaces in multiple dwellings which contain central heat-producing, air-conditioning and other equipment shall be ventilated to the outer air, and air from these spaces shall not be recirculated to other parts of the building.
(3) 
Ventilation shall be provided in unheated attics, spaces below flat roofs and crawl spaces. Location and net areas of ventilation openings shall be such as to minimize deterioration of structural members from condensation or other causes, in conformity with generally accepted standards.
A. 
Stairs, both interior and exterior, shall be of sufficient width in conformity with generally accepted standards so as to serve the occupants.
B. 
Railings or equivalent shall be provided on open portions of stairs, balconies, landings and stairwells.
A. 
Safe, continuous and unobstructed exit shall be provided from the interior of the building to the exterior at street or grade level.
B. 
Exits shall be arranged, constructed and proportioned so that occupants may escape safely from the building in case of emergency.
C. 
In one- and two-family dwellings, in addition to a primary exit from the building, there shall be provided a secondary exit or, in lieu thereof, one or more exit openings for emergency use.
D. 
In multiple dwellings, approved exits shall be provided.