NFPA Journal

In November, a fire started on the 11th floor of a high-rise apartment building in San Francisco. Five people who lived in the unit where the fire originated were injured. Three additional units sustained heavy damage as a result of the fire. A total of 23 units were determined to be uninhabitable from either smoke or water damage. Perhaps even more concerning is that in 2018, 30 residents were displaced from the same 22-story building due to a fire that affected units on five floors.

The building did not have sprinkler protection in the dwelling units. When it was constructed, it was not required to include total automatic sprinkler coverage—it was required to have fire sprinklers only in the basement storage areas, along with water hoses in elevator lobbies. The building is one of many that are grandfathered into legislation that allows them to continue to be inhabited without requiring additional sprinkler protection. In response to this recent fire, it was reported that San Francisco will now likely seek to change the law, requiring all high-rise residential buildings, regardless of age, to be retrofitted with automatic sprinkler protection.

The level of protection required for high-rise buildings varies across the country, a result of jurisdictions adopting legislation that modifies model codes with local ordinances. While the trend seems to be moving to more sprinkler mandates, there are jurisdictions where either all existing high-rise buildings, or a specific category of existing high-rise buildings such as residential, remain unsprinklered. These high-rise buildings are said to be grandfathered—a term not recognized by the compliance approach taken by NFPA 101®, Life Safety Code®—into older legislation that permits them to remain in use without sprinkler protection, even if more modern sprinkler requirements are in place for newer buildings. Resource allocation and the cost of retrofits are often unfortunate factors in decisions where building safety and sprinkler protection are set aside.

Through the 2018 edition of NFPA 101, existing high-rise apartment occupancies have required full automatic sprinkler protection unless one of two alternatives is met: automatic sprinkler systems are not required where every dwelling unit has exterior exit access (in accordance with 7.5.3 of the code), or when buildings have an approved, engineered life safety system (ELSS).

An ELSS is a custom building fire protection system that is designed to provide equivalent protection to a full building sprinkler system. The ELSS must include any or all of the following: partial automatic sprinkler protection, smoke detection systems, smoke control systems, compartmentation, and other approved systems. It is required to be developed by a registered professional engineer specifically experienced in fire and life safety system design and must be approved by the authority having jurisdiction. During the planning phase, the designer should meet with the AHJ to determine whether an ELSS is acceptable in lieu of automatic sprinklers.

The 2021 edition of NFPA 101 includes a proposed change to the sprinkler alternatives for existing high-rise apartment buildings: there is no longer an option to introduce a new ELSS, although previously approved ELSS developed in accordance with the appropriate provisions can remain. Instead, existing high-rise apartment buildings without a previously approved ELSS, or where every dwelling unit does not have exterior exit access (in accordance with 7.5.3 of the code), must be protected throughout with sprinklers by January 1, 2033. This change reflects the code’s reliance on, and strong support for, automatic sprinkler protection as the preferred and most effective method of life safety during fire.

It is interesting to note that other model codes, including NFPA 1, Fire Code, have required sprinkler protection for all existing high-rise buildings, regardless of occupancy, for several editions. In the case of NFPA 1, an existing high-rise building is required to be protected with a sprinkler system within 12 years of adoption of the code.

Once implemented, ELSS cannot be neglected and should not be altered without analysis of the modifications on their equivalent design and level of protection. To help ensure that these systems continue to achieve their purpose, those previously approved ELSS are now required to be maintained in accordance with the approved design documents and applicable standards. If the system cannot be properly maintained, then the building must default to the requirement of being protected throughout by an automatic sprinkler system.

For more information on changes to high-rise building sprinkler requirements in the 2021 edition of NFPA 101, visit a recent blog post on NFPA Today at nfpa.org/high_rise_sprinklers. 

Kristin Bigda is technical lead for Engineering Technical Services at NFPA. NFPA members and AHJs can use the Technical Questions tab to post queries on NFPA 101 at nfpa.org/101. To follow the progress on the upcoming edition of the code, visit nfpa.org/101next.

Kristin Bigda is technical lead for Engineering Technical Services at NFPA. NFPA members and AHJs can use the Technical Questions tab to post queries on NFPA 101 at nfpa.org/101. Top photograph: Getty Images