SOME OF OUR MOST TRANSCENDENT moments occur in assembly occupancies, including churches, restaurants, theaters, and stadiums. From a fire and life safety perspective, assembly occupancies have also hosted some of our most horrific events. NFPA’s list of deadliest public assembly and nightclub fires in United States’ history is a compendium of almost unimaginable loss, from the Iroquois Theater fire in Chicago in 1903 (602 deaths) to the 1942 Cocoanut Grove nightclub in Boston (492 deaths) to the Beverly Hills Supper Club fire in Southgate, Kentucky, in 1977 (165 deaths) to The Station nightclub fire in West Warwick, Rhode Island, in 2003 (100 deaths). The concentration of people in these occupancies, combined with a host of potential egress problems, have given many of these fires a tragic prominence in the country’s public safety history.
That’s in part why egress—the ability to get out of a building safely and quickly—is such an elemental concept in both the renovation and new construction of assembly occupancies. It’s also why the egress schematic—or what NFPA 101®, Life Safety Code®, refers to as the “life safety floor plan”—is such an important tool for stakeholders in these projects.
Added to the 2015 edition as a part of several enhancements to the Life Safety Evaluation (LSE) provisions for assembly occupancies, a life safety floor plan should not be confused with a “floor diagram,” which the Life Safety Code defines as a diagram “reflecting the actual floor arrangement, exit locations, and room identification” in hotels and dormitories that aids residents in an emergency evacuation. As part of an LSE, the life safety floor plan is a detailed instrument dedicated to all matters related to egress—a set of drawings that combines a building’s layout with information on occupant load, egress capacity, and egress routes from any occupied space within the building out to the public way. These plans can help architects, designers, owners, plan reviewers, authorities having jurisdiction (AHJs), and building users recognize and address potential egress issues, especially if they’re created early in the design process. They can also document means of egress compliance, leaving the design team free to devote its energy to the more creative aspects of the building’s design.
In many cases, though, life safety floor plans are not completed, or are done as an afterthought late in a project. While the plans are not required for most buildings, they are mandated as a part of the LSE. The 2015 edition of NFPA 101 requires life safety evaluations for assembly occupancies with capacities greater than 6,000 people, for indoor festival seating exceeding 250 people, and where occupancies use the more favorable smoke-protected assembly seating exit capacity factors.
The LSE is a comprehensive analysis of not only the physical structure, but also of the types of events it is expected to host, how the facility management staff is trained, and evaluation of how various emergencies will be handled if they occur within the building or exterior to the building. The life safety floor plans are an essential part of this process. Every project is ultimately subject to approval by an AHJ, who is likely to have egress as a top-of-mind concern; the development of a life safety floor plan, even where an LSE is not required, is an invaluable way to avoid egress-related problems, delays, and cost overruns.
We’ve asked Ray Battalora, a project manager with Aon Fire Protection Engineering Corporation in Richardson, Texas, and Jack Sawyer, an associate with Eskew Dumez Ripple Architects (EDR) in New Orleans, to outline 10 components of life safety floor plans and to demonstrate how the plans worked with an actual assembly occupancy renovation—in this case the recently completed makeover of the 800- seat Civic Theatre, a performing arts center in downtown New Orleans.
1 - "Tell the Story" of egress
Ray Battalora — For the last 15 years, I’ve conducted life safety evaluations on dozens of large and complex assembly occupancy or mixed occupancy projects, including stadiums, arenas, student union buildings, entertainment venues, and large outdoor graduation events—projects ultimately accepted by AHJs. From that experience, I know that the life safety floor plan is an important way to visualize and document the occupant load, occupant flow paths, egress capacity, and other details of assembly occupancies and of structures with multiple occupancies containing assembly occupancies. When you’re preparing to create such a plan, think in terms of a narrative, of an event with a beginning, middle, and end. (A life safety narrative is also a required component of the LSE.) The plan should tell the egress story to the AHJ, who should be able to easily view calculations and notes that illustrate how the egress system works, from start to finish. No one, especially the AHJ, should have to do any homework to confirm the plan’s compliance with the Life Safety Code.
Jack Sawyer — The Civic Theatre opened in 1906 and is New Orleans’ oldest historic theater. The building sat empty for 25 years before renovation work began in 2011. The physical condition of the building, as well as changes to the surrounding neighborhood, necessitated a renovation plan that changed the building’s egress patterns. The theater’s existing exterior fire escape stairs, for example, which provided egress from the upper seating levels, were deteriorated beyond repair and replacing them was problematic. Since the original theater included more seats than needed in the renovation, we thought we might be able to eliminate the fire escape stairs, and began working on a set of egress planning diagrams to answer our questions. These diagrams were some of the first drawings we did on the project, and they were continually updated as we moved through the design process.
We consulted with Ray Battalora, who helped us with questions related to altering the building’s egress patterns. As the design progressed, Ray also helped us develop our egress diagrams into more detailed life safety floor plans, which became powerful tools as we “told the story” of the project to our AHJ and made determinations on required improvements to life safety systems.
2- Consider the visual presentation
RB — Guidance on creating life safety floor plans is located in the 2015 edition of NFPA 101. The details for new assembly occupancies are included in Chapter 12, and information on existing assembly occupancies is included in Chapter 13.
Typically, a set of plans is organized vertically so that the first, or top, schematic is the highest building feature, such as a penthouse or roof, and the bottom schematic is the lowest level, such as a basement or crawl space. Organizing the plans in this manner is especially helpful for irregularly shaped buildings and for enlarged basements. Mezzanines should be shown on their respective floor levels or have their own life safety floor plans. Color can be used for occupant flow lines and for the comparison of occupant load and egress capacity during evaluations or draft versions. For example, red can indicate non-compliance, such as an egress feature with insufficient capacity, and green can indicate compliance.
JS — The Civic Theatre is a historic venue with 800 seats spread across the first floor, balcony (second floor), and gallery (third floor). The seating on the first floor is removable, with adjustable-height platforms that allow the floor to be reconfigured as tiered rows or as a flat floor, which can be level with the stage or set low for stage viewing. The adjustable floor also allows for seating arrangements that include standing patrons (festival seating) on the first floor and seated patrons on the upper levels. The Civic Theatre is fully sprinklered and includes a remotely monitored fire alarm system.
EDR’s approach to life safety floor plans, including those we created for the Civic, is to strip away all the superfluous details on a set of base floor plans and then layer in egress-related information in the form of symbols, dimensions, and notes. This method assures that all necessary building-related notes and dimensions from the matching architectural plans are visible. EDR also combines the first floor with a site plan so that all ground-level egress issues, including any involving access to the public way, can be seen immediately on one plan.
The legibility of these plans is always an issue, and EDR prints them at a larger scale periodically to make sure the graphics are clear and legible. Keep in mind that life safety floor plans submitted to an AHJ or used for construction are generally required to be black and white, without any colored line work. While colors can be useful as part of the internal process, the black-and-white restriction requires a little more creativity in differentiating symbols and line work.
3 - Show the space, its uses, and occupant load
RB — As part of telling an accurate and complete story to the AHJ, life safety floor plans should include interior floor plans as well as exterior information. Interior information includes walls, accurate door swing directions, and unique stair identification numbers or letters. Exterior information includes the path to the public way, including exit discharge landings, exterior steps and ramps, landscape features, and drain grates. The story you’re telling is inclusive: show AHJs everything they need to know about the space, such as a permanent exhibit in a theater lobby or the trash dumpster creating a constriction in an alley used for egress. It’s important to remember that compliant egress is also necessary for building maintenance staff, including people working on rooftops, in utility spaces, and in basements.
The plans should also identify the space’s use and occupant load. Each room or space should be named and should include descriptive text on its use, its area, the occupant load factor (net area per person or gross area per person), and the calculated occupant load. The furniture layout should also be shown. This information documents the design intent and helps AHJs perform their reviews. You will need to develop a separate plan for each occupant load scenario for a given space, such as a gymnasium that may be used for basketball games, concerts, graduation ceremonies, or dances.
JS — EDR developed scaled life safety floor plans for the Civic Theatre early in the restoration process. The drawings included converging occupant flow lines showing crowd accumulations, travel distance and common path of travel, fire-rated wall assemblies, and other elements related to life safety.
Occupant loads for the Civic were clearly presented in a series of graphics and separate tables. The intent was to organize the information for quick digestion and then provide values and calculations in the tables. The Civic project included an adjustable ground level seating platform for multiple event types. Instead of producing separate plans for each floor arrangement, we produced seating diagrams showing all the possible arrangements, then used the arrangement with the maximum occupant load as our basis for the life safety floor plan. The seating diagrams were included in the overall drawing set so the AHJ, and later the builders, could quickly understand the possible variations.
4 - Show your relationship to adjoining buildings
RB —The egress story you tell needs to include adjoining buildings, if those buildings are interconnected. Egress from your building may constitute incoming occupant load for a neighboring building, and vice versa, which is why this is an important aspect to address.
Other scenarios you may need to account for in your life safety floor plans include multiple buildings with levels connected by elevated pedestrian walkways; multiple buildings that have basement levels connected by pedestrian tunnels; multiple buildings adjoining each other and separated by fire walls; sections within the same building that are separated by secured, locked doors; exit discharge into outdoor courts with egress to the public way; and fire separation distance and exterior wall rating/opening issues between buildings in accordance with the relevant building code.
JS — While the Civic Theatre project did not have to address adjoining buildings, the plans did include a main entrance alley shared with an adjacent, more recently constructed building. Prior to renovation, new buildings and other features blocked the theater’s original main entrance, which had been accessed via a promenade through the center of a city block.
Because of this change in the urban fabric, a new main entrance was designed for access through a side alley previously used for theater service functions. Patrons would now enter the side alley near the back of the theater, then walk the length of the theater’s exterior before entering the Civic lobby at the new side entrance. An adjacent building included a parking garage exit stair that opened into this alley. The occupant load from that parking garage exit stair was added to the Civic’s life safety floor plan and was used to check against maximum overall occupant load using the alley for egress.
5 - Calculate and show the egress capacity
RB—The egress capacity based on the egress feature clear width has to be known and identified on the plan. The Life Safety Code provides general information on occupant load and egress capacity factors in Chapter 7.
These values are supplemented with other information, including specific egress arrangement requirements from the applicable occupancy chapter: new assembly occupancies, which are covered in Chapter 12, or existing assembly occupancies, which are addressed in Chapter 13. The egress capacity should be shown for all major exit access features, exits, and exterior exit discharge features along the path to the public way. The available egress capacity should be based on actual clear width, either existing or to be constructed, and application of the appropriate egress capacity factor based on occupancy classification.
JS—The life safety floor plans for the Civic project were developed based on several key existing dimensions, including the maximum width available for new stairs connecting the upper seating levels to the ground floor. Because the space for these stairs could not be enlarged—maximum width was set at 62¼ inches—that one key dimension controlled the seat count on the upper levels. The dimensions of the new stairs, along with other egress width dimensions and egress capacities, are shown clearly on the plan for each floor.
6 - Show flow lines
RB—Flow lines are a useful graphical method to route occupants through the egress system. Life safety floor plans should show flow lines originating from rooms or spaces; occupant load accumulated along each flow line; flow lines routed to and through each exit access feature; flow lines routed to and through the building exits; and flow lines routed through the exit discharge and continued to the public way. Flow lines on a large floor may merge, and the combined occupant load is useful for designing adequate egress width for exit access features such as corridors and cased openings. Exterior flow lines from the building may be required to merge with exterior flow lines from adjoining buildings.
JS—The Civic Theatre life safety plans include dashed flow lines documenting the egress sequence from each part of the building. Flow lines were also shown on the exterior where they described converging flow as occupants egress down two parallel alleys leading to the public way.
7 - Compare occupant load and egress capacity at egress features
RB—It is common practice on life safety floor plans to identify each major exit access feature, exit, and exterior exit discharge feature on the path to the public way with a circle bisected by a horizontal line, where the top half of the circle contains the occupant load value (the number of occupants routed to the egress feature) and the bottom half of the circle contains the egress capacity of the egress feature. Alternatively, text can be used to present these values. Either way, the objective is for the plans to clearly illustrate for stakeholders that the egress capacity is equal to or exceeds the occupant load.
JS—EDR adopted a symbol from Aon to fully describe egress width. This symbol is the split cell arrow, as described by Ray, used to identify any door opening or stair. The symbol allows one value to show occupant load allowed (based on clear width) while the other shows the actual number of occupants we proposed would egress through that opening or stair. This simple symbol allows plan reviewers to follow the swell of egressing occupants from point to point ending at the public way, and to understand the egress capacity of each opening or stair that occupants would pass through. The clarity of these symbols in particular is critical for a life safety floor plan to tell an accurate story to the AHJ.
8 - Show compartmentation and fire and smoke resistance
RB—Compartmentation features—building elements such as floors and walls that divide the building into fire compartments and smoke compartments—are integrally related to the means of egress. Those features, including fire walls, fire barriers, smoke barriers, and smoke partitions, should be identified on the life safety floor plan with thick lines, and their fire resistance and any required smoke resisting properties should be noted. Additionally, building elements with compartmentation features—stairways, horizontal exits, elevator hoistway enclosures, and rooms with hazards requiring fire barriers, to name a few—should be shown with their required numerical fire resistance and any required smoke resisting properties.
JS—Theaters are an interesting building type in that the ground-floor volume must also include upper-level seating such as balconies or galleries. As a result, NFPA 101 does not require stairs serving theater balconies and galleries to be enclosed or built as fire compartments. The only interior fire compartments necessary for the Civic Theatre were the two-hour-rated fire barrier and attendant fire curtain required at the proscenium wall, located between the audience and the backstage area, and a one-hour-rated wall separating the stage from the dressing rooms. This protection was provided by backstage walls and the theater’s existing 12-inch-thick masonry proscenium walls, complete with a new proscenium opening fire curtain compliant with NFPA 80, Fire Doors and Other Opening Protectives. Each of these compartmentation features was included in the life safety floor plans.
9 - Show travel distances and paths
RB—Egress travel distances should be shown for individual spaces and for the entire floor to help tell the egress story. Distances should include overall diagonal measurement, dead end travel, common path of travel, and total travel.
JS—The Civic’s egress plan included travel distances in key common path locations such as the dressing rooms and adjacent corridor, but they did not include similar distances for the main seating areas. This decision was based on the fact that the building was to receive a new sprinkler system, compliant with NFPA 13, Installation of Sprinkler Systems, and would therefore have 250 feet of allowable travel distance. This was well over the actual travel distance from any given seat at the upper level, including the distance down either unenclosed main stair to an exit door on the exterior. Where travel distance approaches the permitted maximum, EDR typically includes it, along with the common path dimensions from each space to an exit on the life safety floor plan.
10 - Show egress signage
RB—An egress schematic can be a good place to think through egress signage, since flow lines and exit signage can be developed together. Egress signage details include location, orientation relative to the plane of the wall or door opening, number of viewable sides, and directional arrows.
JS—Only lighted exit signs were required for the Civic Theatre project, so no additional egress signage was included on the life safety floor plan. Instead, this information was included on separate electrical drawings that were also submitted to the AHJ. EDR has included egress signage on the plans for other projects, however, and we find it a valuable communication tool to also share with consultants designing electrical systems.
A cautionary tale
Why should you consider life safety floor plans? Consider what can happen if you don’t.
In one case—a new multi-story building, which included a restaurant/meeting space on the top floor—the calculated occupant load was not completed for the space until midway through the design, and was found to be greater than the egress capacity provided by the two exit stair enclosures. The problem was addressed with a prescriptive code option using horizontal exits; fortuitously, the building floor deck and primary structure down to the foundation provided at least two hours of fire-resistive construction, which is required to support a two-hour fire barrier wall for a horizontal exit. Even so, this represented a compromise, since a two-hour fire barrier wall and one-and-a-half-hour fire door assemblies had to be provided in what was initially envisioned as open space.
During the early stages of design, stairs and their number, location, and size are erasable lines on paper; adding and/or enlarging stair enclosures near the end of the design process (or even during construction) can be costly and very disruptive. Had the occupant load for the restaurant space been calculated earlier, during the program phase of the project, it would have been easy to make one or both of the stair enclosures larger to provide the required egress capacity to serve the floor’s occupant load. A life safety floor plan would have made this problem apparent, and saved a lot of stakeholders from a lot of headaches.
ACK SAWYER, AIA, LEED, AP, is a project manager and an associate with Eskew Dumez Ripple Architects in New Orleans.