Best practices for designing fire, life safety in government buildings

Respondents:

• Chris Ankeny, PE, LC, LEED AP BD+C, Associate/Senior Electrical Engineer, Clark Nexsen, Virginia Beach, Va.
• Mark Chrisman, PhD, PE, Health Care Practice Director/Vice President, Henderson Engineers, Kansas City, Mo.
• Randall Ehret, PE, Technical Director | Electrical, ESD, Chicago
• Todd Garing, PE, LEED AP BD+C, Vice President, Mueller Associates Inc., Linthicum, Md.
• Rob Jordan, PE, FPE, LEED AP, Mechanical Department Manager, Burns & McDonnell, Kansas City,
• Julene May, PE, PMP, Chief, F-35 Beddown Program Management Office, Stanley Consultants Inc., Eielson AFB, Alaska
• Jon Sajdak, PE, Associate Fire Protection Engineer, Page, Austin, Tex.
• Troy Windom, Automation Manager, Dewberry, Raleigh, N.C.

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?

Julene May: Due to the environmental constraints of being unable to use aqueous firefighting foam (AFFF) all new and renovated hangars are incorporating high-expansion foam (HEF) systems. The biggest challenge in implementing HEF systems is the requirement for a complete fire system overhaul for existing facilities. Secondary and/or tertiary effects that need to be accounted for are the potential need to upsize the building’s electrical system and/or transformers.

Todd Garing: Where required by the International Building Code, automatic sprinkler systems are provided within most types of buildings per NFPA 13 Standard and the local authority having jurisdiction (AHJ).

Some of the unique challenges we encounter on federal projects involve a building type that contains gallery space, artifact storage room, vaults or specialized computer/IT spaces. For these areas, we engineer a special automatic sprinkler system, such as a double interlock pre-action system that uses nitrogen or compressed air with water, mist or a clean agent type fire suppression system that uses a chemical, gases or foam agent.

When discovering a challenging space such as an art gallery, artifact storage, computer/IT space, etc. within a building that requires sprinkler protection, coordination should occur between the architect, fire protection engineer, AHJ, the building owner and the building owner’s insurance underwriter to discuss and decide on the best type of fire suppression system to be provided for the particular space.

Historic spaces present unique challenges where routing fire suppression and fire alarm systems without sensitivity can destroy the historic fabric the systems are there in part to protect. Close coordination with all disciplines, thorough understanding of the existing conditions, flexibility and creativity are paramount.

Chris Ankeny: Requirements for the design of secure or classified spaces can be subjective and dependent on specific decisions of the classifying authority. For example, sometimes networked fire alarm panels connected by fiber optic are required so that no wiring penetrates the secure perimeter. Other times, penetrations by conduit may be permitted if there is a dielectric break and/or grounding. Determination of these requirements early in the design process is essential to producing a comprehensive and accurate set of construction documents that can be bid.

Rob Jordan: Fire and life safety projects for federal clients have many additional layers of codes. In addition to the traditional civilian sector codes, there are DOD-specific codes that may limit options usually available on the civilian side. Our team manages these differences through experience and communication with the various government representatives.

When designing DOD facilities, there are many parties involved, including the building’s owner, user, builder, maintainer, as well as the entity paying for the project. It’s sometimes difficult for the authorities having jurisdiction (AHJ) to balance the interests of each party. A user might ask for a unique room to be added to the design, but it’s important for contractors to determine if that party is authorized to ask for that space and only allow if they are the ones directing the design. Communication is key.

Another challenge may also be determining who the AHJ is. It might seem the fire marshal is, but that is not always the case. There is a separate bureaucracy of AHJs not usually involved in the design, construction and inspection process. The AHJs rely on the engineer of record to manage things properly.

Fire and life safety projects require increased coordination with all other design disciplines. We are responsible for helping with the design of many integrated systems. This can include everything from egress requirements with the architect, to shunt-trip breakers with electrical, to damper locations with mechanical. Hazardous material considerations, specialized detection systems and unique storage rack protection are other examples of working across many disciplines of engineering.

How have the trends in fire/life safety changed on such projects?

Jon Sajdak: One of the current trends for fire protection design in these facilities include the use of nitrogen in sprinkler systems. In portions of these facilities where dry pipe systems or preaction systems are provided, nitrogen provides an alternative to air. The nitrogen helps mitigate corrosion in the system and can help extend the life of the system.

Rob Jordan: Codes and standards on fire and life safety projects change frequently and are often more comprehensive with each edition. Trends on fire and life safety projects change with these new codes and standards, so it’s important to stay up to date on the new requirements. A project designed today may have very different standards to adhere to than a project designed in a few years.

Todd Garing: Regarding automatic sprinkler systems, one trend has been the designs of special sprinkler heads being improved each year for use in different types of buildings and spaces.

For example, clean agent fire suppression systems, such as FM-200, NOVEC-1230, Inergen, etc., are always being improved to help protect the environment and ozone depletion in the event of a clean agent discharge. We have also seen increased acceptance of water mist systems for fire suppression.

What fire, smoke control and security features might you incorporate in these facilities that you wouldn’t see on other projects?

Mark Chrisman: Many federal sector facilities have fire protection and life safety features not required in private sector facilities. For example, a two-story office building (business occupancy) under Department of Defense criteria may be required to have a fire sprinkler system, a voice evacuation fire alarm, mass notification system and protected means of egress, while that same building in the private sector may only require protected means of egress or fire alarm system. You might encounter a requirement for a smoke control system more easily on a public sector facility as well because of the large number of codes, standards and criteria that are adopted.

Todd Garing: Often on many of these projects, buildings will have an atrium space, which requires special designs of automatic sprinkler systems to protect the atrium, along with a dedicated smoke control system that must activate when a fire occurs within the atrium. Many government entities are their own Authority Having Jurisdiction and performance-based design is frequently embraced which provides more options to satisfy life safety requirements. Some examples include time-based egress studies and smoke control modeling using computational fluid dynamics.

Jon Sajdak: Many government and military projects have special access control requirements along with mass notification requirements. These typically require coordination with the security or low voltage engineer on the project. In some cases, doors and lock hardware need to be interfaced between the fire alarm and security system to make sure occupant egress can occur during an emergency. Also, mass notification systems are integrated with the fire alarm system on military projects. These systems are voice communication systems that are also intended to alert occupants in the facility during other events such as weather or an active shooter in the premises.

Chris Ankeny: Especially for DOD facilities, combination voice fire alarm/mass notification (or emergency communication) systems are common. Voice fire alarm systems were previously only common in large assembly occupancies, but now most DOD facilities are being provided with them. Additionally, voice fire alarm systems are starting to be seen more often in K-12 schools due to recent changes in the model building codes.

Describe unique security and access control systems you have specified in such facilities.

Jon Sajdak: On a previous military project we faced an issue with elevator recall and access control. In the event of a fire on level one, the secondary elevator recall was set to level two. However, level two was considered a ‘secure’ level and occupants were not permitted to discharge to that level and disperse freely. As a result, an additional vestibule with corridor connections were needed to provide access to exit stairwells. Key card readers were also at the doors of the vestibule to enable authorized occupants to access the level as needed.

Mark Chrisman: On General Services Administration projects, we have seen a wide range of security and access control systems depending on the varying tenants within the building. Spaces involving higher security, like US Marshals or Department of Homeland Security, present challenges depending on the existing building’s active and passive fire safety features and the location of the spaces within. While we can often make the varying levels of security/access control work within a building, half the challenge is often discussions during design to identify what hardware is required where and documenting how it is compliant.

Do you see any future changes/requests to the structural design of these buildings regarding fire/life safety systems?

Mark Chrisman: The types of materials being used for the structural support of the building is continuing to change and be challenged. Recently there’s been a huge push in the private sector to build large, wood structures with mass timber. There are environmental and financial considerations for using wood, but there are also ongoing discussions with the AEC industry and authorities having jurisdiction for how to address adequate fire protection/life safety within the building, as well as how to respond in the event of a fire. It’s likely this will continue in the future and will impact public sector projects in some way.

How has the cost and complexity of fire protection systems involved with government, state, federal, correctional and military projects changed over the years? How did these changes impact the overall design process?

Chris Ankeny: The increasing requirement for emergency communication (or combination voice/fire alarm) systems can result in increased space needed for control equipment, amplifiers, basewide MNS transceivers, etc. Additionally, to provide the required level of intelligibility these systems often require additional notification appliances. For example, on a voice system we are typically providing speakers in all normally occupiable spaces, including private offices.

Mark Chrisman: For department of defense projects specifically, there have been significant changes to the fire sprinkler pressure and flow requirements in the last 10 to 15 years. These have impacted many renovations and, depending on the age of the building and original building sprinkler system design, have required fire pumps and/or water storage tanks, which can impact the project duration and construction cost. However, in some instances it has been the reverse, where the building was designed for more restrictive criteria and the renovation had no impact on schedule or cost.

Jon Sajdak: One trend that is apparent in government and military facilities include moving away from the use of spot type smoke detection devices. Spot type detectors are still installed in required locations such as elevator lobbies and at fire alarm control panels, but the Unified Facilities Criteria (UFC) indicates that detectors shall not be used in any other spaces where they are not required by code. The concern is that the devices are not tested and maintained properly, which can lead to nuisance alarms. Also, smoke detection technology using air-aspirating smoke detection has become more widely used and have systems that are easy to maintain. This reduces the long-term maintenance costs of the spot type smoke detectors.

Todd Garing: When it comes to life safety systems that include fire suppression and detector systems, we offer cost-effective solutions that do not override protecting lives. We inform our clients and owners on the different types of systems available for use regardless of the complexity or type of building. Protecting lives is the most important — always — when deciding on the type of system that should be used.

How have changes to codes, BIM and wireless devices/systems impacted fire and life safety system design for these projects?

Jon Sajdak: Regarding BIM changes, facilities for these types of projects require a high level of development (LOD) and detailed coordination between disciplines. The Fire Protection industry over the past few years has made significant strides in BIM modeling. For example, Revit families are now more widely available for modeling sprinkler system, fire alarm system and other life safety system components. Engineers are able to spatially coordinate these devices to provide adequate clearance and coordinate system requirements between disciplines.

Mark Chrisman: While we have seen the use of wireless devices pushed into the fire alarm market, we are really only seeing them being used in the private sector.

Chris Ankeny: While we typically provide “performance based” design criteria for sprinkler systems and not detailed layout of piping and sprinklers, BIM does allow us to provide a coordinated design on those projects where more specific pipe layouts, etc., are necessary. For example, we are currently designing an aircraft corrosion control facility that has very large ductwork in the paint bay and by doing a detailed system layout for this bay we are able to verify that there is room for piping and hangars. Additionally, some of the intelligent features in BIM allow us to readily generate estimated current load for notification circuits (and consequently estimate the number and location of power booster panels) and more easily prepare life safety drawings.

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