From the Technical Director: Approaches to Designing Fire Safety in Buildings
By Morgan J. Hurley, P.E. | Fire Protection Engineering
Fire protection is typically designed into buildings to achieve one or more fundamental goals: 1
Life Safety. This
goal includes mitigation of injury or death caused by fire to the
public, building occupants and members of the fire brigade. Property Protection. Property protection goals address protection of building contents, historical features and the building itself from fire. Business Continuity. Business
continuity goals are associated with ensuring that an organization can
continue to operate following a fire. Meeting business continuity goals
may require protection of production or manufacturing operations,
critical supplies or other operations essential to an organization's
mission. Environmental Protection. Providing
environmental protection from fire requires designing such that the
fire or runoff from fire-fighting operations does not harm the
environment. For most buildings, goals will be stipulated by the
applicable building code. The goals identified in building codes vary
somewhat by country. Codes in all countries provide life safety and
property protection as goals; however, the degree of property protection
differs among countries. Environmental protection is generally only a
consideration for buildings that contain hazardous chemicals. Continuity
of operations is typically only regulated to the extent that it affects
the public well-being for example, in buildings such as hospitals that
provide critical public services. In other buildings, protection of
mission is only addressed by the building owner, tenant, or insurer, and
is not addressed by building codes.
There is a multitude of ways in which
fire protection can be designed such that these goals are achieved. In
many buildings, fire safety is achieved through a combination of
"active" and " passive" systems. "Active" systems are those that take an
action to control a fire. Examples of "active" systems are sprinkler
systems, fire alarm systems and smoke control systems.
"Passive" systems are systems that are in
place before a fire and require no action to mitigate the effects of
fire. Examples of " passive systems" include structural fire resistance
As with fire safety goals, the approach that is
commonly taken to fire protection differs somewhat from country to
country; however, fire safety approaches can differ more than goals do.
For example, many European and Asian countries emphasize the use of
smoke control systems and passive fire protection strategies to achieve
fire protection goals.
Other countries take different approaches to fire
safety. In North America, active systems such as sprinklers and fire
alarms are used more frequently than in Europe or Asia. Other types of
systems, such as compartmentation, structural fire resistance and smoke
control, are also used, although their use is generally only required in
specific types of buildings. Of course, some buildings do not use
either active or passive fire protection systems.
One reason that approaches to fire safety
differ, is that building codes have evolved differently. A motivation
for changing prescriptive building codes is the occurrence of fire
events that have an unacceptable outcome. Following a fire that has an
outcome that is unacceptable, building codes are modified to prevent
similar events from occurring in the future. However, if the incident
that precipitated the change to the building code is not international
in significance, codes in other countries will probably not be modified.
Other factors can also influence the evolution of prescriptive codes,
such as the availability of locally developed systems or technologies.
The measure of acceptability of
prescriptive codes is generally based on fire losses if the fire losses
associated with a prescriptive code are acceptable to society, the code
is considered sufficient. Therefore, although prescriptive codes may
vary with geographic area, one code is not necessarily superior to
As performance-based codes become more widely used, fire safety
designs will still generally differ among geographic areas because
designers and code officials will tend to select strategies with which
they are familiar. Different types of designs will be used in cases
where unique fire hazards dictate specialized solutions. Additionally,
multinational companies (e.g., hotels) will endeavor to have their
properties as similar as possible, and hence will push for fire safety
designs that are as alike as possible.
With performance-based designs, the
measure of acceptability is whether or not the design team can
demonstrate to the satisfaction of the code official that the fire
safety strategy that they select achieves the fire safety goals. This
will allow designers and building owners more flexibility. However,
designs will likely not differ tremendously from those that have been
The ultimate measure of acceptability of the fire safety
designs, whether it is based on prescriptive code requirements or
performance-based engineering, is fire losses. If the fire losses
associated with local codes are acceptable, the code and design process
is considered sufficient.
1SFPE Engineering Guide to Performance-Based Fire Protection, National Fire Protection Association, Quincy, MA, 2006.