Retail, restaurant and mixed-use facilities: Fire, life safety
Jason Gerke, PE, CxA, LEED AP BD+C
Practice Area Leader – Mechanical/Plumbing | Principal
Wayne Griswold, PE, CFPS
Principal Fire Protection Engineer
Jonathan Robertson, PE, LEED AP BD+C
Associate Principal, Mechanical
Sunondo Roy, PE, LEED AP
CSE: What are some of the unique challenges regarding fire/life safety system design that you’ve encountered for such projects? How have you overcome these challenges?
Griswold: Mixed-use facilities that propose to use nontraditional tenants adjacent to one another is a unique challenge. An emphasis needs to be placed on what the intent of the building is to be used for, but also what the area or space could be used for moving forward. AHJs can be leery of these types of facilities because it isn’t always clear what is happening within tenant walls after construction is completed.
The best way we have found to protect all stakeholders is the use of a fire protection report, which documents the intended function of the space at the time of its inception. This effectively takes a snapshot of the building in time from a fire/life safety system performance perspective and is updated as future tenants move in or as proposed tenants are vetted. While not necessarily ideal, it ensures that newer tenants or occupancy changes don’t compromise the building as a whole.
CSE: How have the trends in fire/life safety changed on such projects?
Griswold: Depending on the budget of the project and the information known throughout the design phase, the projects typically take one of two paths: a conservative or lean approach. A conservative approach generally uses a more robust sprinkler system to allow for prospective tenant flexibility. Another example of a conservative approach is pro-actively using fire rated separations between tenant areas. This is conservative from the standpoint that not all occupancy (i.e., tenants) would require this.
A lean approach involves protecting the building as it is permitted (i.e., core and shell) or specific to the known tenants using it. This methodology addresses the fire/life safety systems for a specific tenant in a specific instance and provide little, if any, conservatism. With this approach, the prospective tenant may be responsible for updating their portion of the mixed-use facility up to code, based on their operations. Each approach is widely used; while having different pros/cons depending on how aggressive the tenant market may be.
CSE: Many restaurants are opting for open, “showcase” kitchens to entertain patrons. How (if at all) has that trend affected your work on fire protection systems on such projects?
Griswold: Showcase kitchens do present some challenges as it subjects patrons of the restaurant to fire/life safety issues that are otherwise typically separated by some form of construction (i.e., fire–rated construction). Facility orientation and proximity of patrons to the kitchen are issues needing consideration when addressing fire sprinkler requirements and kitchen hood sizing and suppression systems selection. Assuming these factors are sufficiently vetted and addressed, a showcase kitchen presents no additional risk to restaurant goers.
CSE: What fire, smoke control and security features might you incorporate in these facilities that you wouldn’t see on other projects?
Griswold: If otherwise not required by the base building code, voice fire alarm systems are preferred in these types of occupancies. Fire/life safety emergency direction given by a person’s voice has been proven to garner better responses related to occupant evacuation. Restaurants or mixed-use occupancies where the egress arrangement may be complex or have a wide range of ambient noise makes successful evacuation more likely than with traditional fire alarm horn/strobe type systems.
CSE: Describe unique security and access control systems you have specified in such facilities.
Griswold: Access control between staffed areas and general public is typically a concern that needs to be addressed as part of the fire/life safety system interface plan. Restaurants tend to be more free-flowing and require less access control or security measures. Where such systems are requested to be used, the interface with the fire alarm system to ensure free mechanical egress is required to ensure patron life safety.
CSE: Do you see any future changes/requests to the structural design of these buildings regarding fire/life safety systems?
Griswold: Based on the lessons learned from recent high-rise façade fires across the world, I anticipate changes to exterior façade requirements. Additionally, how we protect the building from a passive system (i.e., firestopping) standpoint at the exterior wall and floor/ceiling interface needs to be improved to better resist passage of heat and smoke vertically.
CSE: How has the cost and complexity of fire protection systems involved with restaurant, retail and mixed-use projects changed over the years? How did these changes impact the overall design process?
Griswold: As finishes have become more complex in hospitality settings (e.g., foam plastics, light-transmitting plastics), upgraded fire protection systems are a common method of providing alternate code compliance. This may range increased sprinkler densities, unique installations and detection where it may not otherwise be required. As these approaches are atypical, they need to be accounted for in preliminary design as unanticipated additional infrastructure may be necessary.
CSE: How have changes to codes, BIM and wireless devices/systems impacted fire and life safety system design for these projects?
Griswold: BIM technology is constantly evolving in more complex buildings and also in designs where clash detection is desirable to avoid construction delays associated with uncoordinated trades. Fire and life safety systems generally are not intrusive when compared to overall MEP designs. Caveats to this are sprinkler and smoke control systems where shaft enclosure space and/or ceiling space can be limited. We’ve experienced varying degrees of success with BIM projects, although I would expect this to improve as the technology is refined and use is more commonplace.