262 Chapter 11
and regulations to implement laws passed by Congress. These regulations are often national laws that
supersede or supplement local building codes. Each federal agency has its own set of rules and regula-
tions that are published in the Code of Federal Regulations (CFR). Readers should be familiar with the
following governmental agencies that produce building regulations that may impact projects under review:
- Access Board (previously named the Architectural and Transportation Barriers Compliance
Board) - The Department of Energy (DOE)
- The Environmental Protection Agency (EPA)
- The Federal Emergency Management Agency (FEMA)
- The General Services Administration (GSA)
- The Department of Housing and Urban Development (HUD)
- The National Institute of Standards and Technology (NIST)
- Occupational Safety and Health Administration (OSHA)
There are many national organizations that support the organizations that produce codes and stan-
dards and are essential to their development, although they are not themselves directly responsible for
their production. Two such organizations are the National Conference of States on Building Codes and
Standards (NCSBCS), and the National Institute of Building Sciences.
11.5 BUILDING-CODE ELEMENTS AND APPLICATIONS.
Most code requirements for fire and smoke protection are based on occupancy classifications. “Occu-
pancy” refers to the type of use a building or interior space is put to, such as a residence, an office, a
school, or a restaurant. “Occupant load” is a term used to specify the number of people that a building
code assumes will occupy a given structure or portion of it. Occupant-load calculations are based on the
assumption that certain categories of occupancy have greater densities of people than others and that
exiting provisions should adequately reflect this. Load factors are depicted in either gross square feet or
net square feet.
The formula used to determine the occupancy load is:
occupancy load floor area (sq. ft.) occupancy factor.
Thus, the square footage of the interior space that is assigned to a particular use is divided by the
occupant load factor for the occupancy use as given in the code. Occupant load factors help determine
the required occupant loads of a space or building and range from a low of 3 square feet per person for
a waiting space to a high of 500 square feet per person for storage areas. In ascertaining the occupant
load, it is presumed that all parts of the building will be occupied at the same time. If a building or build-
ing area provides more than one use—i.e., has mixed occupancies—the occupant load is determined
by the use that reflects the highest concentration of people.
Types of Occupancy.
Occupancy, as stated, refers to the type of use of the building or interior space, such as a residence, of-
fice, store, or school. An occupancy classification must be assigned to any building or space, and deter-