Special Detailed Requirements Based on Occupancy and Use PDF

4 Special Detailed Requirements Based on Occupancy and Use In addition to the requirements for typical occupancies, the code addresses detailed requirements for specific building types in Chapter 4. The descriptions of the basic requirements for these special detailed uses are abbreviated in this b...

4 Special Detailed Requirements Based on Occupancy and Use In addition to the requirements for typical occupancies, the code addresses detailed requirements for specific building types in Chapter 4. The descriptions of the basic requirements for these special detailed uses are abbreviated in this book. Many of these specialized uses occur infrequently in practice. This chapter touches on the most basic of these special provisions, and when an actual project falling under these provisions is encountered, the detailed provisions in the IBC should be carefully examined. The occupancy of these buildings usually fits into one or more of the typical occupancy groups, but characteristics of these building types require additional code provisions. Examples of such building types are covered and open mall buildings, high-rise buildings, and atriums. A mall is basically a Group M occupancy, but with many stores, large occupant loads, and means of egress that also serve as pedestrian walkways. High-rise buildings are typically Group B or R occupancies with very large occupant loads and are defined as having occupied floors located above fire department ladder access. Atriums have large interior volumes open to pedestrian pathways and to occupied spaces. These buildings need added code consideration above and beyond more typical uses in the same occupancy group. The additional code requirements for these building types are determined by their configurations, not their uses. These provisions are meant to apply over and above the other provisions applicable to their occupancy group classification. After the designer has classified the building by occupancy, the building type must then be examined to see if it meets the definitions for these specialized use groups and thus must also meet the added criteria for them. The process of analysis of use and occupancy should commence with an analysis of how the proposed building fits into the uses and occupancies described in Chapter 3 of the code, and then should be analyzed against the criteria in Chapter 4 to see which, if any, are applicable. SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY AND USE It is worth remembering that the detailed provisions of Chapter 4 of the code relate to and coordinate with the more basic requirements spelled out in Chapter 3 for use and occupancy requirements. The designer as code user should make a progression from the general to the specific in analyzing a building. Begin with the general categorization of uses and occupancies. Then proceed to review the detailed requirements of Chapter 4 for provisions applicable to the building in question. While one may begin the analysis of a specialized use by looking up the detailed requirements, the code is organized to proceed from determining the occupancy first and then applying detailed criteria. Just as one should not read up from footnotes to find table sections that may be misapplied, the user should not work backward in these analyses, as this may lead to erroneous code interpretations. We will go through the specialized building types to describe their distinguishing criteria and touch on the major additional code provisions applicable to them. We will discuss those special uses most likely to be encountered by designers. Note that detailed discussions of many specialized uses have been omitted, as they are not seen frequently. Most are related to Group H occupancies or to process-related special uses. Most designers do not frequently encounter these very specialized structures, or others such as underground buildings or amusement buildings. The criteria applicable to each of these other building types are used as noted above. The occupancy must first be determined before applying the specialized requirements contained in Chapter 4. Many of the sections in Chapter 4 contain definitions of the uses or occupancies to which the special provisions apply. These definitions are listed in Chapter 2 of the code and crossreferenced for location and explanation in the section indicated. Note that although the definitions may seem familiar and similar to common construction terminology, they have very specific meanings in the code. Examine the building design conditions and definitions carefully to determine the applicability of the definition to the building design. This analysis of the definition may also point out necessary modifications to the design to make it codecompliant or reveal the need to reclassify it. • First identify the general use and occupancy group to which the building belongs, and review the requirements contained in Chapter 3. • Group A Assembly • Group B Business • Group E Educational • Group F Factory • Group H Hazardous • Group I Institutional • Group M Mercantile • Group R Residential • Group S Storage • Group U Utility 34 / BUILDING CODES ILLUSTRATED—THE BASICS • Then refer to Chapter 4 and review the requirements for special detailed requirements based on use and occupancy. • Covered and Open Mall Buildings • High-Rise Buildings • Atriums • Underground Buildings • Motor-Vehicle Related Occupancies • Institutional Groups I-2 and I-3 • Motion-Picture Projection Rooms • Stages, Platforms, and Technical Production Areas • Special Amusement Areas • Aircraft-Related Occupancies • Hazardous Materials • Combustible Storage • Spray Application of Flammable Finishes • Drying Rooms • Organic Coatings • Live/Work Units • Artificial Decorative Vegetation • Special Requirements for I-1, R-1, R-2, R-3, and R-4 Occupancies • Hydrogen Fuel Gas Rooms • Ambulatory Care Facilities • Storm Shelters • Play Structures • Hyperbaric Facilities • Combustible Dusts, Grain Processing, and Storage • Medical Gas Systems • Higher Education Labs Institutional Groups I-2 and I-3 The code adds provisions related to Group I-2 occupancies in § 407 and Group I-3 occupancies in § 408 that must be read in concert with those in Chapter 3. Chapter 3 is intended to address the occupancy classification of a building, and Chapter 4 is intended to address detailed requirements for certain uses and occupancies. Code analysis of these occupancy groups requires looking at both sets of provisions together. These are very specialized occupancies with many specific and detailed requirements. The discussion in this chapter of the special requirements for these occupancies is only an introduction. The code user must consult the detailed requirements in the IBC to determine the specific requirements for a specific project. Other Specialized Uses The remaining groups of uses in Chapter 4, beyond those discussed in this chapter, relate to specific uses of buildings or parts of buildings that are infrequently encountered in most occupancies. These include motion-picture projection rooms, stages and platforms, special amusement areas, aircraft-related facilities, and high-piled combustible storage. These are specialized uses not often encountered in the normal course of work and will not be addressed in this book. COVERED AND OPEN MALL BUILDINGS 1 • Anchor building • Anchor buildings have exits separate from the covered mall per § 402.8.4.1. Retail Retail Covered Mall Retail Retail • Anchor building • A covered mall building is a roofed or covered pedestrian area into which two or more tenants have their main entrances. • Covered malls governed by these provisions are limited to three levels at any point and not more than three stories above grade. • Per § 402.7.2, where a covered mall building contains an atrium connecting three or more stories, the atrium shall be provided with a smoke control system in accordance with § 909. • A covered mall building is a single enclosure housing stores, restaurants, and other facilities, each of which has a main entrance onto the mall. • A food court is a public seating area that serves adjacent food preparation tenants. Retail Retail Open malls using the provisions of § 402 are to be treated in a similar manner to covered malls in how they relate to means of egress and major stores. 2 Retail The IBC has added language clarifying that the term “covered mall building” is intended to also include open malls, which are defined as “unroofed common pedestrian ways serving two or more tenants and which do not have more than 3 levels open to each other.” Thus, an open mall is essentially the same as a covered mall, but without a cover over the mall circulation spaces. The open mall is flanked by “open mall buildings,” which, as for covered malls, do not include anchor buildings. 3 Retail Covered and Open Mall Buildings The code provisions in § 402 for covered mall buildings grew out of many years of application of special interpretations of existing codes in response to a then-new building type. It did not fit into the code criteria in use at the time this use type was first developing. Covered malls came into being based on design and retailing innovations. They combine the circulation paths used for means of egress with pedestrian routes. Spaces that might be considered exit discharge areas or safe egress terminations, such as a city street, became exit access areas with enclosures. Multiple tenants have access to the common pedestrian areas. There is a mixture of large department store type uses, termed “anchor” buildings, and smaller shops that open on the mall. It is also expected that there may be a mixture of other uses such as cinema and food court assembly areas as well as major anchor uses that are interconnected by the mall. • Anchor buildings are not considered to be part of a covered mall building. Note that anchor stores are to be part of the analysis of open space separation distances per § 402.2. SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY AND USE / 35 COVERED AND OPEN MALL BUILDINGS • 20' (6096) min. clear opening between roof extensions into an open mall. • An open mall is an unroofed common pedestrian way serving multiple tenants and not exceeding three levels. 3 2 1 • 20' (6096) min. clear opening between balcony extensions into an open mall. • Gross leasable area (GLA) is the total floor area available for tenant occupancy, measured from the centerlines of joint partitions to the outside of tenant walls. All tenant areas, including areas used for storage, are to be included in the GLA. 5,000 sf/15 sf (465 m2/1.39 m2) per occupant = 334 occupants Total Occupant Load: = (200,000/39) + 334 = 5129 + 334 = 5463 occupants 36 / BUILDING CODES ILLUSTRATED—THE BASICS Retail Retail Retail Retail To determine the occupancy of the food court, use Table 1004.5 and allow 15 sf (1.39 m2) net per occupant in the food court seating area (assembly without fixed seats, unconcentrated, with tables and chairs): Retail To determine the occupant load factor (OLF) for the mall, use Equation 4-1: OLF = (0.00007) (GLA) + 25 OLF = (0.00007) (200,000) + 25 = 39 sf (3.62 m2) per occupant Open Mall Retail Retail Assume: Retail Gross Leasable Area (GLA) = 200,000 sf (18,580 m2) + A food court having an area of 5,000 sf (465 m2) + An assembly use with fixed seating for 500 (included in the 200,000 sf (18,580 m2) of the GLA) • Open mall perimeter line per § 402.1.1. Retail Example for Determining Occupant Load per § 402.8.2 • Anchor building • Anchor buildings are not considered to be part of an open mall and are to be outside of the open mall perimeter line per § 402.1.1. • Anchor building outside perimeter line of open mall • Assembly occupancies with an occupant load of 500 or more are to be located in the covered mall building such that their main entrance is immediately adjacent to a principal entrance to the mall. Not less than one half of the assembly area means of egress width is to open directly to the exterior of the covered mall building. Main exits may open into the central open mall area in an open mall building. • Whenever travel distance to the mall from inside a tenant space is more than 75' (22 860) or the tenant space has an occupant load of 50 or more, two means of egress are to be provided from the tenant space. The second means of egress could be directly to the outside or into a rated corridor or exit passageway. • Note that per the Exception to § 402.8.2.1, tenant spaces attached to the mall building but having a means of egress system independent of the mall building need not be considered as gross leasable area for the occupant load calculations since they do not contribute any occupant load to the mall means-of-egress system. COVERED AND OPEN MALL BUILDINGS • The minimum width of exit passageways from a mall is 66" (1676). The code provisions for covered and open malls rely on several basic ideas: 1. First is the provision of multiple clear paths of exit with widths sufficient to accommodate the occupant load, which is calculated according to criteria in this section. 2. Second is the requirement that the increased building area be offset by separation from other buildings by at least 60' (18 288) of permanent open space to allow safe egress areas for occupants. This permanent open space allows covered mall and anchor buildings to have unlimited area for all but Type V construction. Note that the open space may be reduced under certain conditions as illustrated below. 3. Third is the requirement that potentially hazardous uses such as parking structures be separated from the mall, either by a minimum distance or by construction type (fire barrier with a fire-resistance rating of 2 hours). 4. Fourth is a requirement for provision of active fire protection in the form of sprinklers, standby power, and a central fire department operations area. 3-hour wall 60' (18 288) 40' (12 192) • Anchor buildings are defined as having direct access to the covered mall. By definition, they are required to have means of egress independent of the mall. They are analyzed as separate buildings and are not to be considered as part of the covered mall building. • There are to be no means of egress from anchor building to mall. Openings are allowable. The openings may be unprotected in Types IA, IB, IIA, and IIB construction. 40' (12 192) MALL 60' (18 288) 60' (18 288) • Parking structures must be separated from the mall by construction type (fire barrier with a fire-resistance rating of 2 hours), or if separated by distance, the distance is to meet the requirements of Table 705.5. 60' (18 288) 40' (12 192) 40' (12 192) • The maximum distance of travel from any point in a covered mall to an exit is 200' (60 960). For an open mall building the distance is measured to the perimeter line. EXIT • The maximum distance of travel from any point in an individual tenant space to an exit or entrance to the mall is 200' (60 960). If this travel distance exceeds 75' (22 860) or if the occupancy load exceeds 49, a second exit from the tenant space is required per § 402.8.3. • Perimeter line at open mall building. • The building area must be separated from other buildings by at least 60' (18 288) of permanent open space to allow safe egress areas for occupants. This permanent open space allows mall and anchor buildings to have unlimited area for all but Type V construction. • Per § 402.2 the permanent open space, normally 60' (18 288), may be reduced to 40' (12192) under certain conditions: • The reduction may occur along no more than 75% of the perimeter of the entire facility, including both the mall and anchor buildings. • The exterior walls facing the reduced open space must have a fire-resistance rating of 3 hours and openings must have a fire protection rating of 3 hours. • There can be no E, H, I, or R occupancies within the facility; thus, hotels and apartment buildings may not be in the facility if it utilizes the reduced distances. SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY AND USE / 37 COVERED AND OPEN MALL BUILDINGS • Per § 402.6.2 and § 402.6.3, kiosks and play structures are to meet minimum criteria for combustibility to minimize their contribution of fuel or smoke in case of a fire in the mall. • Kiosks and similar structures must be separated by a minimum horizontal distance of 20' (6096). • There is to be a minimum of 10' (3048) clear exit width between tenant spaces and any obstructions, such as kiosks, benches, or food courts. Thus, placing such elements in a 20' (6096) wide mall could require the width of the mall to be increased to provide the minimum clear egress widths. Aggregate egress width is to be at least 20' (6096). • Malls are to be at least 20' (6096) wide (or wider as required by the occupant load). • The roof opening width and space between projected floors above grade at open malls is to be at least 20' (6096). 20' (6096) min. • Anchor buildings are to be separated from the covered mall building by 3-hour fire walls per §706. Per exception to §402.4.2.2, 2-hour fire barriers per §707 are acceptable if the anchor building is not more than 3 stories and of the same occupancy uses as the covered mall building. • Walls at major stores facing an open mall are to comply with the requirements of Table 705.5. • Central fire-department operations area. • An emergency voice/alarm communication system and a standby power system to power the communication system are required for covered mall buildings exceeding 50,000 sf (4645 m 2 ) in total floor area. • All rooms or areas containing fire protection systems must be identified for use by the fire department. 38 / BUILDING CODES ILLUSTRATED—THE BASICS Generator • Fire partitions between tenant spaces must have a minimum fire-resistance rating of 1 hour as per § 402.4.2.1 and § 708. • No fire separation is required between a tenant space and the mall. The exterior wall is also not required to be rated by the tenant spaceseparation provisions. • Grilles and similar security closures are allowed at exits of open storefronts as long as they are not closed during normal business hours. • The mall itself is considered as a corridor, but is not required to be fire-rated if it is more than 20' (6096) wide, and all egress width provisions are met per § 402.8.1. HIGH-RISE BUILDINGS As building technology allowed advances in high-rise construction, the buildings often outstripped code provisions needed to address the new conditions impacting fire and life safety. High-rise buildings, made possible by innovative structural technology and elevators for transporting occupants, exceed the capabilities of firefighting procedures used for shorter buildings. They have occupied floors above the reach of even the longest ladders carried by fire department vehicles. • Note that the criteria for determining if a building is a high-rise is measured to the highest occupied floor, not to the height of the building construction, and not to an occupied roof. Note that high-rise egress systems are based on the occupant loads and egress requirements spelled out elsewhere in the code (see Chapter 10). Stairways are the primary means of egress, with elevators typically serving only firefighting functions as necessary. • The definition of a high-rise building in § 202 is based on the height at which typical firedepartment extension ladders and hose streams can effectively fight a fire. Thus a building with an occupied floor more than 75' (22 860) above the lowest level of fire-department access is defined as a high-rise. Firefighting in a high-rise assumes that the firefighters must enter the building and go up inside the building to fight a fire. With the advent of ever-taller buildings and in light of lessons learned from the September 11, 2001, World Trade Center disaster, a subset of requirements for “super high-rise” buildings, which are those taller than 420' (128 m) in height, has been added to the IBC. Most of these provisions are found in § 403 but many others are scattered throughout the code, most notably in Chapter 10, where additional means-ofegress provisions are required in such buildings. We will highlight these provisions with a notation where they apply to our discussion or illustrations. Note that requirements for “Fire Service Access Elevators” for buildings more than 120' (36 576) in height are found in Chapter 30. SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY AND USE / 39 HIGH-RISE BUILDINGS • Emergency phone every fifth floor in each required stairway where the doors to the stairway are locked. • § 403.4.5 requires that emergency responder communication coverage is to be provided per § 510 of the IFC. Code requirements for high-rises are a combination of passive and active fire-protection measures. • The buildings must be constructed of noncombustible materials or of mass timber construction. • Shafts and vertical penetrations must be enclosed to prevent the spread of smoke and fire. • § 403.3 requires that automatic fire sprinklers be installed throughout high-rise buildings. • In Seismic Design Categories C, D, E, or F, a secondary water supply capable of supplying the required hydraulic sprinkler demand, including the hose stream requirement, for up to 30 minutes is required. • § 403.2.1 allows a reduction in fire-resistance rating if the automatic sprinkler system has control valves equipped with supervisory initiating devices and waterflow initiating devices for each floor. This reduction does not apply to high-rise buildings over 420' (128 m) in height. • § 403.4.1 requires smoke detectors connected to an automatic fire-alarm system per § 907.2.13.1. • Where shafts have sprinklers installed in them at their tops and at alternate floor levels, the shaft fire-resistance rating may be reduced to 1 hour. • This reduction does not apply to exit enclosure shafts or to elevator hoistway enclosures, or to any shafts in buildings over 420' (128 m) in height, whether sprinklered or not. • § 403.4.4 requires an emergency voice/alarm communication system to be activated with the operation of any automatic fire detector, manual fire-alarm box, or sprinkler device. • § 403.4.6 requires a firefighting command center per § 911 in a location approved by the fire department. • § 403.4.8 requires standby and emergency power systems to be located in a separate room enclosed with 2-hour fire-resistance-rated fire barriers and fueled by a 2-hour supply of on-site fuel. These power systems are required for the operation of systems necessary for evacuation or for firefighting, such as elevators, smoke control systems, emergency lights, and firefighting systems and operations. Confer with the AHJ to determine the Fire Code distinctions and requirements for standby and emergency power systems. • § 403.5.3 requires stairway doors that are locked from the stairway side to be capable of being unlocked simultaneously from the fire command center. 40 / BUILDING CODES ILLUSTRATED—THE BASICS HIGH-RISE BUILDINGS • Buildings greater than 420' (128 m) in height or in Risk Categories III and IV per Table 1604.5 (i.e., hospitals, large assembly high-rises, and essential services) are to have hardened exit and elevator shafts per § 403.2.2. The hardening criteria are based on ASTM C1629/C1629M standards. Concrete or masonry walls are deemed to meet these requirements. • Per § 403.5.2, a third egress stair is required for buildings other than R-2 occupancies greater that 420' (128 m) in height. (Note the requirement is dependent on building height, not just for Occupancy Categories III and IV.) • Each sprinkler zone in buildings greater than 420' (128 m) in height is to have two fire sprinkler risers, with each riser supplying sprinklers on alternate floors. • Note that per the Exception to § 403.5.2, a third egress stair is not required if occupant selfevacuation elevators complying with § 3008 are provided. For all high-rises: • Per § 403.5.1, stair enclosures are to be separated by at least 30' (9144) or not less than 1/4 of the length of the maximum diagonal dimension, whichever is less. Where there are three or more stairs, at least two must meet this criteria. • For high rises greater than 120' (36 576) in height, there are to be at least two fire-service access elevators complying with § 3007. There are additional requirements for high-rise buildings that are more than 120’ (36 576) in height: 1,000 psf >120’ (35 576) SFRM Minimum bond strength (psf) • Minimum bond strength of sprayed fire-resistant materials (SFRM) varies based on building height, with the major break occurring at a height of 420' (128 m). 500 psf 430 psf 0 75' (22 m) 420' (128 m) > 420' (128 m) Building Height • In buildings of Type IV-A and IV-B mass timber construction, required fire pumps are to be served by water mains in two different streets. [These dual connection requirements also apply to Type I buildings more than 420’ (128 m) in height. • Such buildings are to have fire service access elevators per § 3007 as well as multichannel emergency voice communication systems per § 907.2.13.3. SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY AND USE / 41 ATRIUMS Atriums are an innovative building type that require a specific building-code response. The code requirements in § 404 for atriums combine aspects of malls and high-rise fire and life safety provisions. As for covered malls and high-rise buildings, the code requires that a mixture of active and passive fire-protection measures be provided in atriums. Atrium buildings, however, rely more heavily on active systems for fire and life safety. • The exit travel distance through the atrium is regulated by § 1017.3.2. • Buildings containing atriums must be fully sprinklered throughout the building. There are limited exceptions to § 404.3 for certain areas, but the basic design assumption should be that such buildings are fully sprinklered. • Openings into the atrium may be glazed if special fire-sprinkler protection is provided. The code defines an atrium to be a vertical space that is closed at the top and connects two or more stories in Group I-2 and I-3 occupancies and three or more stories in all other occupancies. The greatest concern about atrium fire and life safety involves the control of smoke. Atriums that connect more than two stories, other than those in Group I-2 and I-3 occupancies, are required to have smoke management systems conforming to § 909. These interconnect elaborate systems of detectors, fans, and controls to contain or move smoke to allow safe egress for occupants of atriums. Note that smoke control is required in atriums connecting two or more stories in I-2 and I-3 occupancies. There is a special case not requiring smoke control for atriums open only to the bottom two levels. To qualify for this exception, two conditions must be met: 1. All stories above the lowest two levels must be separated from the atrium with shaft enclosure protection per § 713.4. 2. Only the two lowest levels may be open to the atrium. 42 / BUILDING CODES ILLUSTRATED—THE BASICS • By definition, an atrium is an opening that connects two or more stories in Group I-2 and I-3 occupancies and three or more stories in all other occupancies. In other words, it is considered to be an interconnected series of floor openings inside of a building that create a physical connection and a common atmosphere between floor levels of the building. The code definition assumes that an atrium has an enclosed top. The description of an atrium is partly determined by what it is not. • A building wrapped around an open space creates a court, not an atrium. • Balconies in assembly areas or mezzanines do not create an atrium. • A series of openings through floors that are enclosed by a shaft such as an enclosed stair, elevator, or ductwork does not create an atrium. • Buildings with two or three levels of openings that meet the criteria for a covered mall may be more properly classified as mall buildings. The definitions of mall and atrium are mutually exclusive and are not intended to be interrelated. ATRIUMS • § 404.3 requires an approved automatic fire-sprinkler system be installed throughout. • The sprinkler requirement does not apply to the portion of a building adjacent to or above an atrium if that portion is separated from the atrium with 2-hour fire barrier walls or horizontal assemblies, or both. • Automatic sprinkler protection for the ceiling of an atrium is not required if the ceiling is more than 55' (16 764) above the floor. • § 404.4 requires a fire alarm system complying with § 907.2.14. • § 404.5 requires a smoke-control system to be installed in accordance with § 909 so that the atrium space is kept clear of smoke and can be used as a safe means of egress. • Means to exhaust air for smoke-control system. • § 404.6 requires atrium spaces to be separated from adjacent spaces with 1-hour fire-barrier walls. • Exceptions to § 404.6 allow escalators and stairs to penetrate horizontal assemblies when they are protected with draft curtains and closely spaced sprinklers. • Glass walls separating an atrium space from adjacent spaces are permitted if they serve as smoke barriers and can be wetted upon activation of automatic sprinklers spaced along both sides at 6' (1829) on center and installed between 4" and 12" (102 and 305) away from the glass. Only one side need be protected if there is no walkway on the atrium side. • The 1-hour protection may be omitted for the adjacent spaces of up to three floors of the atrium if the spaces are included in computing the atrium volume for the design of the smoke-control system. • § 404.7 requires an emergency standby system per § 909.11 be available to power the smoke control system. • Two-story atrium does not require smoke control per Exception to § 404.5, unless the building houses I-1 Condition 2 or I-2 occupancies where a smoke-control system is required at two or more stories. • Per Exception 4 to § 404.6, fire barriers are not required where a smoke control system is not required. • When the egress is not through the atrium space or the exit access travel distance occurs at the level of exit discharge, the distance is to comply with § 1017.2. Where the exit access travel distance starts at a level other than the level of exit discharge, § 404.9 and § 1017.3.2.3 limit the exit-access travel distance to 200' (60,960). • Means to allow air in for smoke-control system as make-up air for smoke exhaust. SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY AND USE / 43 MOTOR-VEHICLE-RELATED OCCUPANCIES Building codes have traditionally had a great deal of difficulty classifying and addressing parking structures and garages. There is a longstanding perception among code writers that there are inherent dangers for vehicles carrying flammable fuels and emitting noxious gases. Yet buildings housing these types of uses have had a generally good safety record. Because of special concerns regarding these occupancies expressed in predecessor codes, § 406 has grouped these uses into a separate category that can be considered a distinct occupancy group. Revisions to § 406 place all of the general requirements for motor-vehicle-related occupancies into a single group at the front of the section. Items that are common for all the various uses covered by this section, and which used to appear in each subsection, are now stated once in the various subsections in § 406.2. The common criteria are meant to apply to the many varied uses covered by this section: private garages and carports; public parking garages, whether open or enclosed; and fuel dispensing stations and repair garages. Note that there are some special conditions in the subsections that will augment the general provisions discussed here. • All automatic openers are to be listed and labeled per UL 325. This is a safety standard for electric operators rated 600 volts or less for doors, draperies, gates, louvers, and windows. • Private garage door opener § 406.2.1 Automatic Garage Door Openers and Automatic Gates This subsection highlights the broad range of applications for § 406.2. These provisions are applicable to quite different uses, ranging from single-family home garages to multistory public parking garages. • Public parking garage entry gate § 406.2.2 Clear Height The clear height of each floor level in vehicle and pedestrian traffic areas in all motor-vehicle-related uses is to be not less than 7' (2134). Canopies under which fuels are dispensed are to have a taller clear height in accordance with § 406.7.2. Note that in parking garages serving van accessible parking, 98" (2489) clearance is required per Standard ICC A117.1, which is adapted into IBC Chapter 11. • Minimum of 7' (2134) clear in all motor-vehicle uses 44 / BUILDING CODES ILLUSTRATED—THE BASICS MOTOR-VEHICLE-RELATED OCCUPANCIES § 406.2.3 Accessible Parking Spaces Where accessible parking is required, accessible parking spaces, access aisles, and vehicular routes serving accessible parking are to be provided in accordance with § 1106. Stall dimensions will be as required by Standard ICC A117.1. § 406.2.4 Floor Surfaces Floor surfaces are to be of concrete or similar noncombustible and nonabsorbent materials. Floors areas used for parking are to be sloped to facilitate the movement of liquids to a drain or toward the main vehicle entry doorway. The surfaces of vehicle fueling pads in motor-fueldispensing facilities are to be in accordance with § 406.7.1. Exceptions to § 406.2.4: • Asphalt parking surfaces are permitted at the ground level in public parking garages and private carports. • Floors of Group S-2 open or enclosed parking garages are required to have a sloped surface. This requirement was absent for several code cycles and reinstated in the 2021 IBC. We recommend a 2% slope to provide drainage and still meet disabled access requirements. • Slip-resistant, nonabsorbent, interior floor finishes meeting certain finish criteria are permitted in repair garages. • See Chapter 11 for dimensions. • Concrete floor is sloped to a drain or toward garage doorway. • No openings between sleeping rooms and motor-vehicle-related facilities. § 406.2.5 Sleeping Rooms Openings between a motor-vehicle-related occupancy and a room used for sleeping are not permitted. § 406.2.6 Fuel Dispensing The dispensing of fuel is only permitted in motor fuel-dispensing facilities that are in accordance with § 406.7. If there are conflicts between § 406.2 and § 406.7, the requirements of § 406.7 are more specific to the proposed use and are to govern. • See § 406.7 for heights required at motor vehicle-fuel dispensing facilities, which will supersede the 7' (2134) clear height allowable under § 406.2.2. SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY AND USE / 45 MOTOR-VEHICLE-RELATED OCCUPANCIES § 406.2.7 Electric Vehicle Charging Stations This is a new section recognizing the increased presence of electric vehicles (EV). This is to address how to treat them, if provided. It does not require them. Where provided, electric vehicle charging stations are to be installed in accordance with NFPA 70 and are to be listed and labeled in accordance with UL 2202 and UL 2594. Accessibility to electric vehicle charging stations is to be provided in accordance with Chapter 11. • EV charging station signage. E V ELECTRIC VEHICLE CHARGING STATION • EV charger with bollard protection • EV charger plug-in at vehicle § 406.2.9 Equipment and Appliances Equipment and appliance requirements that were previously included with each motorvehicle use have been consolidated into this section. Additional requirements are to be found in the International Mechanical Code and the International Fuel Gas Code. § 406.2.9.1 Elevation of Ignition Sources Equipment and appliances having an ignition source and located in the uses covered by § 406 are to have the ignition source elevated such that the source of ignition is not less than 18" (457) above the floor. For the purpose of this section, rooms or spaces that are not part of the living space of a dwelling unit and that communicate directly with a private garage through openings shall be considered to be part of the private garage. Per an exception, elevation of the ignition source is not required for appliances that are listed as being flammable-vapor ignition resistant. 46 / BUILDING CODES ILLUSTRATED—THE BASICS • Appliance with ignition source (e.g., flame), such as a water heater or furnace • Motor-vehicle-related use • 18" (457) minimum MOTOR-VEHICLE-RELATED OCCUPANCIES § 406.2.9.1.1 Parking Garages Connection of a parking garage, which would include residential parking garages and open and enclosed parking garages, to a room in which there is a fuel-fired appliance, is to be by means of a vestibule providing a two-doorway separation, except that a single door is permitted where the sources of ignition in the appliance are elevated in accordance with § 406.2.9. Compliance with that section would include appliances not needing elevation since they meet the exception by being listed as flammable-vapor ignition resistant. This requirement is not applicable to overhead appliance installations complying with § 406.2.9.2 or § 406.2.9.3. Motor-vehicle-related uses break down into four general categories: 1. Private garages or carports 2. Public parking garages 2a. Open parking garages 2b. Enclosed parking garages 3. Motor-fuel dispensing stations 4. Repair garages • A vestibule with two doors, one to the “parking garage” and one into the building, is required per § 406.2.9.1.1 if the appliance location criteria shown at right are NOT met. This is to prevent non-combusted fuel fumes from entering the adjacent space. • The language “parking garage” in this section should be read as applying to both public parking garages (open or enclosed) and private garages. • A vestibule with two doors is not required if the fueled appliance is located on a pedestal that is at least 18" (457) above the floor or the appliance is listed as flammable-vapor ignition resistant. • Private garage, 1,000 sf (93 m 2) maximum. • 1-hour fire barrier minimum separation between private garages. Private Garages and Carports Private garages or carports are for private use and meet the common definition of what we all think of as parking for housing. These are typically considered Group U occupancies. Separation requirements are contained in § 406.3.2.1. Note that one- and two-family dwellings and their accessory structures such as garages are intended to be regulated by the International Residential Code. • An enclosed garage abutting a house is to have a minimum of one layer of 1⁄2" (12.7) gypsum board on the garage side. Where rooms extend over the garage a minimum of 5/8" (15.9) type-X gypsum board is to be used at the ceiling for separation. • Doors between the garage and house are to be solid wood or solid-core doors at least 13/8" (35) thick or complying with § 716.2.2.1. • Door is to be self-closing and self-latching. • Appliances that are mounted overhead are to be not less than 8' (2438) above the floor in public garages per § 406.2.9.2, and not less than 6' (1829) above the floor in private garages per § 406.2.9.3. A vestibule with two doors is not required where appliances with ignition sources are mounted meeting this height criteria. § 406.3.1 Group U–Private Garages • Minimum clear height in private garages is to be the same as for other motorvehicle uses per § 406.2.2. SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY AND USE / 47 MOTOR-VEHICLE-RELATED OCCUPANCIES Parking Garages § 406.4 classifies public parking garages into open parking garages and enclosed parking garages. Open Parking Garages Open parking garages are multiple-vehicle facilities used for parking or the storage of vehicles where no repairs take place. These are typically classified as Group S-2 occupancies. They are to be of Types I, II, or IV construction per § 406.5.1. To meet this definition, the amount and distribution of openings are specified in § 406.5.2 of the code. Because these openings are distributed in a manner that provides cross-ventilation for the parking tiers, no mechanical ventilation is required. 7’ (2134) minimum clear • § 406.5.8 requires standpipes per § 905.3. h l8 l1 l7 H l2 • § 406.4.1 requires guards in accordance with § 1015. • Per § 406.4.2, vehicle barrier systems not less than 2'9" (835) high are to be placed at the end of drive lanes and at the end of parking spaces that are more than 1' (305) above adjacent grade. Vehicle barriers are to be in accordance with § 1607.10. l3 l6 l4 Overall Height l5 L W • Per § 406.4.4, vehicle ramps are not to be used as pedestrian ramps unless pedestrian facilities are provided (walkways) and the ramp has less than a 1:15 (6.67%) slope. • The total area of openings on a tier must be at least 20% of the total perimeter wall area of that tier. h × [l1 + l2 + l3 + l4 + l5 + l6 + l7 + l8] ≥ 20% of [H × (2W + 2L)] [l1 + l2 + l3 + l4 + l5 + l6 + l7 + l8] ≥ 40% of [2W + 2L] 48 / BUILDING CODES ILLUSTRATED—THE BASICS • § 406.5.2 requires uniformly distributed openings on two or more sides for the natural ventilation of open parking garages. • The aggregate length of openings on a tier must be at least 40% of the total perimeter of the tier. Interior walls are to be at least 20% open, with uniformly distributed openings. • Although openings on a third side are not required, openings on opposing sides are preferred for crossventilation. • Table 406.5.4 determines the allowable floor areas and heights of open, single-use parking garages for private vehicles according to type of construction. The gradelevel tier is permitted to contain an office, waiting, and toilet rooms having a combined area of not more than 1,000 sf (93 m2). Such areas need not be separated from the open parking garage. • § 406.5.5 permits area and height increases for open parking garages having a greater percentage of openings along a greater perimeter of the building and under specific conditions of use. MOTOR-VEHICLE-RELATED OCCUPANCIES Enclosed Parking Garages Enclosed parking garages are similar to open parking garages except that the amount of wall enclosure relative to the building area does not allow them to be considered as open garages. Because they do not meet the criteria for open parking garages and are considered enclosed, mechanical ventilation is required to compensate for the lack of cross-ventilation. • Means to get exhaust air out for mechanical ventilation of the parking garage per § 406.6.2 and IMC. • Rooftop parking is permitted. • Sprinklered per § 406.6.3. • 7' (2135) minimum clear height at each floor level. Motor-Fuel Dispensing Facilities These uses include motor-vehicle “service stations,” which are typically freestanding structures and are considered as Group M occupancies. Note the references to the Fire Code in which additional construction detail requirements are contained. • Vehicles are to be fueled on a concrete surface or other approved paving with an acceptable electrical resistance level. • The allowable heights and areas for enclosed parking garages are limited to the allowable heights and areas specified in § 504 and 506 as modified by § 507. • Means to get fresh air in for mechanical ventilation of the parking garage. • Canopies are to have a clear height of not less than 13'6" (4115) to the lowest projecting element of the canopy to allow vehicles to drive under the canopy. Repair Garages Repair garages are repair facilities not otherwise classified as motor-fuel dispensing facilities. The limitations on hazardous materials will dictate whether these facilities are considered as Group S or H occupancies. They are considered as Group S-1 occupancies when they do not use or store hazardous materials in quantities sufficient to require classification as a Group H occupancy. These facilities are required to be separated by fire barriers when in mixed-use conditions and treated as separated occupancies. S-1 occupancies may be treated as nonseparated occupancies per § 508.3, but H occupancies will always require separations. • Repair garages to be sprinklered per § 406.8.3. • Repair garages are to be ventilated per the International Mechanical Code with controls at the entry to the garage. SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY AND USE / 49 SEPARATIONS AT DWELLING AND SLEEPING UNITS Separations in I-1, R-1, R-2, R-3, and R-4 Occupancies In either nonseparated occupancies per § 508.3 or separated occupancies per § 508.4, there is still a requirement to provide separations at dwelling units, sleeping units, and supervised residential facilities. § 420 contains these requirements. § 420.2. Separation Walls. Walls separating dwelling units in the same building, walls separating sleeping units in the same building, and walls separating dwelling or sleeping units from other occupancies contiguous to them in the same building shall be constructed as fire partitions in accordance with § 708. M • Walls between differing occupancies must be rated to protect sleeping/dwelling units in the same manner as the walls between the units themselves. R-2 (I-1) (R-1) R-2 R-2 R-2 • Walls between units to be fire partitions per § 708. • Where sleeping units include private bathrooms, walls between bedrooms and the associated private bathrooms are not required to be constructed as fire partitions. • Corridor walls per Table 1020.2. Corridor R-2 R-2 50 / BUILDING CODES ILLUSTRATED—THE BASICS R-2 R-2 R-2 • Where sleeping units are constructed as suites, walls between the bedrooms and associated living spaces are not required to be constructed as fire partitions. • Separation requirements also apply to horizontal assemblies between stacked units. These separations are to be per § 711.