Index of Sections

SECTION 335B - LIGHT AND VENTILATION
Code	Plain English
335B.1 General. Code provisions pertinent to the designated residential area of an individual F-7 Occupancy shall comply with Section 1203 and minimums as provided herein. The remaining area of the individual F-7 Occupancy shall be provided with light, ventilation, and sanitation appropriate to an F-1 Occupancy. Alternative means of ventilation pursuant to Appendix Chapter 12 may be utilized.	335B.1 General. Natural Light and Ventilation must be provided wherever possible in live/work spaces in the form of : 1) For light: windows and/or skylights whose total area is not less than 10% of the floor area of that room 2) For ventilation: operable portions of windows, operable skylights, or doors whose combined total area is not less than 5% of the area of that room. Chapter 12 in the UBC which provides for alternate means, i.e. mechanical ventilation, should be referred to for specific details.
335B.2 Light. If due to legal or physical constraints the requirements for natural light in an existing building are not readily achievable, natural light may be provided by means of exterior glazed openings with an area of not less than one-twentieth of the superficial residential floor area of the individual JLWQ with a minimum of 5 square feet if additional artificial light to meet the requirements of the building official is provided.	335B.2 Light. Sometimes it is impossible to provide the required 10% natural light. In live/work, that number can be reduced to 5% of the floor area of the unit but not smaller than five square feet–as long as sufficient artificial (electric) light is provided. If the sleeping area of an individual space is separated from its required source of natural light by more than 25 feet measured horizontally, then the floor area of the sleeping area (only) shall be doubled and added to the designated floor area of the residential area in calculating the required natural light area for a space. It is particularly important to provide natural light for the sleeping area of a live/work space. Therefore this provision states that if the sleeping space is over 25 feet from its required source of natural light, its area should be counted twice in calculating the total required natural light.
335B.3 Ventilation. If due to legal or physical constraints the requirements for natural ventilation in an existing building are not readily achievable, natural ventilation may be provided by means of exterior openings with an area of not less than one-fortieth of the superficial residential floor area of the individual space or JLWQ with a minimum of 2-1/2 square feet if additional mechanical ventilation to meet the requirements of the building official is provided.	335B.3 Ventilation. Sometimes it is impossible to provide the required 5% natural ventilation. In live/work, that number can be reduced to 2.5% of the floor area of the unit but not smaller than 2.5 square feet–as long as sufficient mechanical ventilation to compensate for this lower amount of lower amounts of natural ventilation is provided. Normally this would mean ventilation equipment capable of continuously providing two air changes per hour in the room(s) in question, except bathrooms, which require full air changes per hour when their fans are on. If the sleeping area of an individual space or JLWQ is separated from its required source of natural ventilation by more than 25 feet measured horizontally, then the floor area of the sleeping area (only) shall be doubled and added to the base superficial floor area of the residential area in calculating the required natural ventilation area for an individual space or JLWQ. It is particularly important to provide natural ventilation for the sleeping area of a live/work space. Therefore this provision states that if the sleeping space is over 25 feet from its required source of natural ventilation, its area should be counted twice in calculating the total required natural ventilation.

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