What’s New in 2009 Edition of the International Building Code
Posted Mon March 01 2010 in News Desk
In the world of code consulting and building design, we can obtain a glimpse into the future by reviewing the changes to the recently released 2009 Edition of the International Building Code (IBC). We at Rolf Jensen & Associates, Inc. (RJA) want you to be prepared for the future by understanding some of the implications of the newly released 2009 IBC.
The 2009 IBC contains too many additions, alterations and deletions to be adequately addressed within this short article. However, analysis of the new edition suggests two developing trends within the broad spectrum of changes. The 2009 Code includes changes that affect buildings regardless of height or occupancy classification, while many of the more wide sweeping changes in the Code pertain to the requirements for high rise buildings, whose impetus in many cases can be traced to the extensive study of the World Trade Center events of 9/11. Therefore initial discussions within this article will incorporate the changes common to both high rise buildings and various other occupancies. Lastly, this article will discuss those changes relating solely to high rise buildings, all with a focus on helping you identify some of the broad design issues impacted by the new requirements of the 2009 IBC.
General Changes
The following provisions highlight the breadth of the changes and identify how they pertain to buildings of various heights and occupancies. The following are only a few examples of changes indicating the breadth of requirements modified in the 2009 edition of the Code.
1. The 2009 edition has eliminated the reduced egress width capacity factor for buildings having an automatic sprinkler system. Under the new provisions, all egress components are evaluated equally for all occupancies, regardless of the presence of automatic sprinkler protection. This change is designed to bring the IBC in line with the more restrictive NFPA 101, Life Safety Code and NFPA 5000, Building Construction and Safety Code egress widths.
a. The stairway egress width capacity factor has been changed for non-Hazardous (H) and non-Institutional (I-2) occupancies to 0.3 inches (7.2mm) per occupant, Section 1005.1. This change is an increase of 0.1 inches (2.5mm) per occupant when automatic sprinklers are present. There is no change to sprinklered protected ‘H’ and ‘I’ occupancies.
b. The non-stairway egress components capacity factors of a building have been changed for non-Hazardous (H) and non-Institutional (I-2) occupancies to 0.2 inches (5.08mm) per occupant, Section 1005.1. This change is an increase of 0.05 inches (1.3mm) per occupant for all occupancies other than Hazardous (H) and Institutional (I-2) when automatic sprinklers are present. There is no change to sprinklered protected ‘H’ and ‘I’ occupancies.
2. After much scrutiny, the 2009 IBC introduced significant changes for elevators and stairways. A majority of the changes are associated with the new high rise requirements and will be discussed later in this article. However, one common change now permits both elevators and stairs to be used for accessible means of egress without the traditional area of refuge or access requirements associated with a horizontal exit. In buildings where automatic sprinklers are installed throughout the following may apply:
a. Elevators are not required to have access from an area of refuge or horizontal exit, Section 1007.4.2.
b. Stairways are not required to contain areas of refuge, Section 1007.3.3.
3. The frequently implemented shaft enclosure section pertaining to vertical openings, often used as an alternative to classifying a vertical space as an atrium, has been altered, Section 708.2.
a. Exception 7 to the shaft enclosure requirements was modified slightly. The most prominent change to this Exception is the removal of the provision allowing a means of egress stair to be located within the vertical space. In contrast, the 2006 IBC allowed the shaft enclosure to contain a required means of egress open stair where allowed by Section 1020.1.
b. Additionally, Section 708.2 was modified to include two new exceptions to the shaft enclosure requirements: elevator hoistway enclosures are not required when only serving a parking garage, and shaft enclosures around mechanical supply or exhaust ducts are not required when the ducts are within and serve only a parking garage.
4. Luminous egress path markings are now required in many occupancy groups where occupied floors are more than 75 feet (22.9 m) above the lowest level of fire department vehicle access, per Section 1024.
5. The allowable building height is reduced for certain occupancies. The allowable building heights for all occupancies and construction types are provided in Table 503.
a. Storage (S) and business (B) occupancies of Type IIB and IIIB construction had the allowable height reduced by one-story from the 2006 edition of the IBC
b. Mercantile (M) occupancies of Type IIB and IIIB construction had the allowable height reduced by two-stories from the 2006 edition of the IBC.
High Rise Changes
The changes within the 2009 IBC have a dramatic impact on the habitable space of high rise buildings. A high rise remains defined as “a building with an occupied floor located more than 75 feet (22.9m) above the lowest level of fire department vehicle access1.” The new edition of the code introduces the concept of sub-high rise groups: high rises, high rises over 120 feet (36.6m) and the new ‘super’ high rise for buildings over 420 feet (128m) in height. In this article, the 2009 IBC changes have been grouped into three segments: all high rises, high rises over 120 feet, and ‘super’ high rises.
All High Rise Changes
Two major changes pertaining to all high rises relate to smoke removal systems and the use of elevators for occupant self-evacuation.
1. Natural or mechanical ventilation should be included for the removal of smoke in the post fire stage, per Section 403.4.6. This may include operable windows or exterior panels potentially affecting the building skin.
2. Elevators can also be used for occupant self-evacuation, per Section 403.6.2. Many specific requirements affecting many disciplines are necessary for an elevator to be used for occupant evacuation. One such requirement is the elevator should open into lobbies with a 1-hour fire-resistance rating and follow a significant number of other specific requirements in Section 3008. These lobbies also have minimum size requirements with 3 square feet per person (0.28m2) for at least 25% of the floor occupant load, per Section 3008.11.4.
High Rise Over 120 Feet Changes
High rises over 120 feet are required to have a fire service access elevator, per Section 403.6.1. This elevator is required to open into lobbies with a 1-hour fire-resistance rating and a minimum area of 150 square feet (14m2) per Section 3007. The fire service access elevator is required to have direct access to an exit enclosure that also contains a standpipe hose connection.
Super High Rise Changes
The rare and highly specialized ‘super’ high rise structures are new to the 2009 IBC. A few of the new ‘super’ high rise classification code changes are summarized as follows:
1. An additional exit stairway above the minimum number of exits is required unless an elevator meeting the requirements for occupant self-evacuation is installed, per Section 403.5.2.
2. No reduction for the fire-resistance rating of building elements is permitted even when automatic sprinkler systems are installed, per Section 403.2.1.1.
3. Elevator hoistway enclosures and exit enclosures are required to meet structural integrity requirements pertaining to resistance to impacts, per Section 403.2.3.
Conclusion
As discussed above, the 2009 IBC changes are broad, yet capable of being summarized to include those affecting; all occupancies, and those specific to high rise buildings. Several of the new changes have significant impact on the habitable space available for an owner considering a new construction project, a major renovation or an architect designing such a project. At present, few, if any, jurisdictions have formally adopted the 2009 Edition of the IBC. Nevertheless, it is helpful to understand the developing trends within the IBC as we await the implementation of the 2009 IBC by the various jurisdictions. For further assistance with 2009 IBC changes or other fire, life safety or security change management strategies please contact your local RJA office.
By: Nicholas E. Ozog, P.E. Nick is an Associate based in the Chicago office of RJA. He can be reached at (312) 879-7200 or .(JavaScript must be enabled to view this email address).
1. International Code Council, International Building Code, 2009 Edition
2. International Code Council, International Building Code, 2006 Edition
3. International Code Council, 2009 IBC Update – International Building Code
Leave a comment
Comments for this post
There are no comments for this entry yet.