A. General:
1. Install windows in outside walls to provide natural light and ventilation in all habitable rooms.
2. Windows in habitable rooms, whose areas provide the light and ventilation necessary to comply with the following requirements, are considered required windows. All windows in addition to these, and also windows in rooms other than habitable rooms, are considered nonrequired windows.
3. The area of glazed portions of doors located in exterior walls may be included when necessary in determining compliance with the above requirements.
4. Provide natural light and ventilation in all rooms, as required below.
B. Habitable Rooms: Habitable rooms are rooms designed to be used for living, sleeping, eating, or cooking.
1. Total glass area, including glass walls, glass blocks, windows and exterior glazed doors, not less than eight percent (8%) of floor area of room. Ventilating area, not less than four percent (4%) of floor area of room. Under covered porches, increase area to not less than six percent (6%) of floor area of room. Kitchens shall be provided with natural light of not less than seven percent (7%) of floor area, including area occupied by equipment. Under covered porches adjacent to kitchen, increase glass floor area of kitchen. Ventilation area in kitchen shall be not less than 3.5 percent of entire floor area of room. When kitchen is not located on outside wall, artificial lighting may be used.
2. Forced ventilation or air conditioning may be substituted if it provides one complete air change every thirty (30) minutes.
C. Borrowed Light And Ventilation Between Rooms:
1. Unless separately lighted and ventilated by windows which provide the required areas, the floor area of two (2) habitable rooms may be combined in computing required light and ventilation areas.
2. The common wall between such rooms shall contain an opening, the area of which shall be not less than sixty percent (60%) of the area of the wall separating these rooms.
D. Bathroom And Water Closet Compartments:
1. Window in an exterior wall or skylight. Glass area for bathroom only, minimum of eight percent (8%) of floor area but not less than three (3) square feet or artificial lighting may be used.
2. The ventilating area must be a minimum of four percent (4%) of the floor area or gravity or mechanical exhaust connected to outside louvered vent must be installed. Vents must be in or near ceiling. Minimum duct dimension for gravity ventilation, three and one-half inches (31/2"); minimum area thirty five (35) square inches. For mechanical ventilation exhaust one CFM per each square foot of floor area.
E. Basements: Basements provide light and ventilation by windows or doors in exterior walls, with both glazed and ventilating area, not less than two percent (2%) of the floor area. An escape access is required (see subsection 8-2-4C of this chapter).
F. Recreation Rooms: Recreation rooms provide light and ventilation by windows or glazed doors in exterior walls.
1. When located in a separately enclosed space in the basement, the glazed and ventilating area shall be not less than four percent (4%) of floor area. Artificial lighting and ventilating can be substituted.
2. When located above basement level, glazed area shall not be less than eight percent (8%) of floor area, ventilating area not less than four percent (4%) of floor area.
3. Provided, that an air exhaust of one-half (1/2) CFM per each square foot of floor area may be substituted.
G. Utility Rooms: A utility room is a room or area enclosed or unenclosed where major housekeeping appliances, laundry facilities, and sometimes including water heating devices, are located.
1. Windows or doors, in exterior walls with ventilating area not less than four percent (4%) of floor area, or
2. Duct or ducts to outside area, minimum total free area two percent (2%) of floor area.
3. Laundry chutes and dumbwaiters shall be provided with self- closing doors or dampers.
H. Heater Rooms:
1. Required Combustion Air: The required combustion air provides fixed combustion air to any confined space which encloses heating equipment by means of ducts arranged to supply air from outside of the confined space. Ducts shall be located: one 12-inches from the top of the space and one 12-inches from the bottom of the space and sized based on the Btu input rating of all equipment located in the space.
Exception: Louvered door may be substituted for the required ducts provided that the louvered door has sufficient openings and the adjacent space is large enough to provide the required combustion air supply.
2. Screening: Duct shall be screened and have free area at least equal to free area of flues or vents to which the equipment is connected. Other requirements pertaining to heating requirements see NFPA pamphlet no. 31 for oil and "Metalbestos Gas Vent And Chimney Sizing Handbook".
I. Basementless Spaces (Crawl Spaces): Area beneath the bottom of floor joists and the ground below.
1. Provide a sufficient number of foundation wall vents to assure a total ventilating area equivalent to one square foot for each fifteen (15) linear feet of exterior wall.
2. Number of vents, minimum of two (2).
3. Locate vents to provide cross ventilation wherever possible.
4. No vents required for crawl spaces, one side of which, exclusive of structural supports such as piers, chimney foundations, etc., is to open to a ventilated basement, provided the total area of ventilating openings is two percent (2%) of the basement area plus the area of the basementless space.
5. In each vent opening install corrosion resistant screening, maximum one-eighth inch (1/8").
6. Crawl space depth minimum twenty four inches (24") between bottom of floor joists and/or girders and finish ground area below (see subsection 8-3-2F3 of this title).
J. Attics And Air Space Between Ceiling And Flat Roofs:
1. To eliminate the problem of moisture condensation on roof framing in cold weather and to permit the escape of heat in hot weather, screened ventilation of all attic and air spaces between ceiling and flat roofs is required.
2. Provide effective fixed ventilation in all spaces between roofs and top floor ceilings by replaceable or nonferrous screened louvers.
3. Net ventilation area for each separate space to be not less than one-three hundredths (1/300) of area of house at top plate. Where possible, locate vents to provide effective cross ventilation (see section 8-3-24, figure A-1, of this title).
4. For flat roofs, blocking and bridging shall be arranged as to not cause interference with the movement of air. (Ord. 2008-09-01, 9-24-2008)