• <br />floor exterior walls. This limit in NFPA 1 and the IFC <br />is 150 feet for buildings without a complete sprin- <br />kler system. For fully sprinklered buildings, NFPA 1 <br />permits this distance to be increased to 450 feet; <br />the IFC leaves this decision up to the discretion of <br />the code official. Further, NFPA 1 requires that the <br />road extend to within 50 feet of an exterior door <br />providing interior access. <br />The distance from the building to a road or fire <br />lane is sometimes referred to as "setback dis- <br />tance. " NFPA 1141 has additional guidelines for <br />access locations versus building location, with vari- <br />ations depending upon building size, height, <br />sprinkler protection, and separation from other <br />buildings. <br />Perimeter Access <br />The options available for attacking a fire increase as <br />more of a building's perimeter becomes accessible <br />to fire apparatus (Figure 2.3). A concept, known <br />as "frontage increase, " appears in the IBC and <br />NFPA 5000. If a structure has more than a certain <br />percentage of its perimeter accessible to fire <br />apparatus, these codes allow the maximum size <br />of the building to be increased. Ideally, the full <br />perimeter would be accessible. <br />During renovations, designers should use partic- <br />ular caution to ensure that the perimeter access <br />continues to meet the NFPA requirements of fire <br />(Fig. 2.3) A combination <br />of two public roads and <br />two private fire lanes pro- <br />vides full perimeter <br />access to this building. <br />12 <br />and building codes. The original building site may <br />have been based on a frontage increase. Changing <br />the amount of perimeter access can result in non- <br />compliant building size. <br />Number of Fire Lanes <br />A single access route is a basic requirement in both <br />NFPA 1 and the IFC. However, both codes allow the <br />code official or AHJ to require additional access <br />routes due to various factors that could inhibit <br />access (such as terrain, climate, or vehicle conges- <br />tion). NFPA 1141 requires two access routes for <br />buildings over two stories or 30 feet in height. <br />Multiple fire lanes should be as far removed from <br />one another as practicable. <br />Turnarounds <br />Long, dead-end fire lanes or roads should provide <br />a means for fire apparatus to turn around. Both <br />NFPA 1 and the IFC require turnaround space for <br />dead-ends that are more than 150 feet long. There <br />are a number of configurations that facilitate turn- <br />ing maneuvers. These include, "T turn, " "Y turn, " <br />and round cul-de-sac style arrangements (Figures <br />2.4 and 2.5 for NFPA diagrams). NFPA 1141 <br />requires a 120-foot turnaround at the end of dead- <br />ends more than 300 feet long. Turnaround dia- <br />grams also can be found in Appendix D of the IFC. <br />OSHA <br />Occupational Safety and 128 <br />Health Administration <br />