1 | Building Codes

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Lecture 2 Codes Gary Parker
1 Building Codes
Analysis of the organization, intent and use of
codes in general and the International Building
Code IBC in particular Reasons why the codes
exist and how they form an integral part of the
design criteria for every building project. The
more you know about the code, the more it can
become a tool for design rather than an
impediment. The better the underlying criteria
for code development and the reasons for code
provisions are understood, the easier it is to
create code-compliant designs. Early
understanding and incorporation of code-compliant
design provisions in a project reduces the
necessity for costly and time-consuming rework or
awkward rationalizations to justify dubious code
decisions late in project documentation, or even
during construction.
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Brief History
If a builder builds a house for someone, and does
not construct it properly, and the house which is
built falls in and kills its owner, then that
builder shall be put to death. (Hammurabis Code
of Laws, ca. 1780 BC) Chicago developed a
building code in 1875 to placate the National
Board of Fire Underwriters who threatened to cut
off insurance for businesses after the fire of
1871. The first model codes were written from
the point of view of insurance companies to
reduce fire risks. Model codes are developed by
private code groups for subsequent adoption by
local and state government agencies as legally
enforceable regulations.
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Three Model-Code Agencies
The first major model-code group was the Building
Officials and Code Administrators (BOCA), founded
in 1915, currently located in Country Club Hills,
IL The International Conference of Building
Officials (ICBO) was formed in 1922, presently
located in Whittier, CA. The first edition of
their Uniform Building Code was published in
1927. The Southern Building Code Congress
International (SBCCI) was founded in 1940,
Birmingham, AL. They publish the Southern
Building Code. The ICBO Uniform Building Code
was used West of Mississippi The BOCA National
Building Code was used North-central,
North-east The SBCCI Standard Building Code was
used Southeast
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International Code Council and the IBC
International Code Council (ICC) was formed in
1994 with representatives from three major
model-code groups. Their first achievement,
despite differences, was that the organization of
each code became the same, thus allowing direct
comparisons. International Building Code (IBC)
published and maintained by representatives of
three agencies, the International Code Congress,
in Falls Church, VA In addition International
Residential Code (IRC) Americans with
Disabilities Act (ADA). It is a federal
civil-rights legislation, an enforced law, rather
than just a code. ADA Accessibility Guidelines
(ADAAG) Federal Fair Housing Act (FFHD)
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Adoptions of Codes by States, Counties and Cities
The three major regional differences still exist.
For instance, until the IBC was adopted, Georgia
adopted more codes according to the Standard
Building Code Larger cities such as Los Angeles,
New York City, Chicago and San Francisco adopt
many revisions to the model codes, sometimes
having no basis on the model-codes. It is
imperative to check first what kinds of codes or
regulations are adopted by the county, city or
the state in which the project is located.
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Specialized Codes the AHJs
Life Safety Code (NFPA-101) published by the
National Fire Protection Association. This codes
serves as the basis for the egress portion of
other model codes. Hospital and federal projects
use NFPA-101. Fire codes are typically
considered maintenance codes. They are intended
to provide for the public safety and the daily
operation of a structure. Planning, zoning,
fire and building officials that have something
to say about building are known as Authorities
Having Jurisdiction (AHJ). Often, there are
overlapping or duplicity of jurisdictions. It is
imperative to determine first which codes and
standards are to be enforced for a project and by
which agency.
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Legal Basis for Codes Standard of Care
Priorities
The model codes have no force of law unto
themselves. Only after being adopted by a
governmental agency, do they become enforceable
under the police powers of the state, county or
city. Determine what kinds of construction
require application of code. Some remodeling
work is exempt from code regulations. One
exception is the ADA which is a civil-rights law
and is not enforced by building officials, while
still not relieving the owner from obligations
under the ADA. Codes are legally and ethically
considered to be the minimum criteria to be
met. The basis for building-code development is
the safeguarding of the public, while having a
strong component of property protection.
Sprinklers help both public and buildings.
Security measures against burglary might
interfere with life safety of occupants.
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Future Trends Performance vs. Prescriptive
Codes
At the present condition, the IBC is prescriptive
in nature. It is developed to mitigate concerns
by creating specific and prescribed responses to
problems that have been identified. For instance,
an assumed problem is falling over an edge higher
then 30 above the adjacent grade. The solution
guardrails of 42 height are required for
differences in grade exceeding 30. Note a
handrail is not a guardrail. Performance codes
define the problem and allow the designer to
devise a solution. The word performance refers
to the problem definition and to setting
parameters for deciding if a solution solves the
problem. For instance, the building shall allow
all of its prospective occupants to safely leave
the building in case of fire. The language of
modern performance based codes is an
objective-based one. Objective What is to be
accomplished? (Example, prevention from falling
30) Functional Statement Why do we want this?
(We want to safeguard occupants from accidentally
falling from a height that might result in
injury) Performance requirement How is this to
be accomplished? Guardrails. (might become
prescriptive)
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2 Navigating the Code
The key word to remember about how all building
codes are developed and how they work is intent.
The intent of the author of a building code
section is to solve a specific design problem
with prescriptive words. Designers also have
intent as they are trying to achieve certain
functional or formal goals in the design of the
building. Designers should measure their own
intent for the design against their
interpretations of the intent of the code. When
examined together, the intent of the code and
that of the design solution should be
concurrent. The responsibility for
understanding, applying and fulfilling the
requirements of the code always rests with the
design professional. Approvals by the AHJ do not
relieve the designer of social and licensing
responsibilities to maintain the health, safety
and welfare of society.
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Intent and Interpretation
Each section of the code was developed to solve a
certain problem. Sections are organized into
chapters based upon common themes, but usually
are developed in isolation from one another with
little attention to continuity of the whole
document. Code language usually arises from a
specific issue the code writer wishes to address
based on experience or upon a construction or
life safety issue. The writer then makes the
requirements general so that they apply to more
typical conditions than the specific instance
that generated the concern. The intent of the
code is a crucial idea to understand. Why is a
much more important question that what when you
are puzzled by the actual language of a code
passage. Do not try to memorize passages from
the code, rather learn the organization of the
code.
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Alternate Means and Methods
The alternative is to be approved when the
proposed design is satisfactory and complies with
the intent of the provisions of this code, and
that the material, method or work offered is, for
the purpose intended, at least the equivalent of
that prescribed in the code in quality, strength,
effectiveness, fire resistance, durability and
safety. ( 104.11)
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Alternate Means and Methods
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Code interpretations
Designers and code officials approach
interpretations from quite different
perspectives. The designer is trying to make
his design solution compliant with the code while
satisfying project requirements. The AHJ
examines the solution for compliance with the
code being unaware about the practical
requirements of the building design. When
differences occur, the designer and AHJ work
together to reconcile the intent of the design
solution with the intent of the code
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Documenting Code interpretations
Every project should receive a detailed code
analysis that is recorded as a permanent part of
the permit documents All code interpretations
and citations should have a reference to the code
sections in order to allow retracting steps in
the code analysis This figures shows the minimum
required items Also, site plan, floor plan,
detail egress requirements, exit discharge paths,
exit quantities and locations.
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Using the Code

• 1 Classify the building according to occupancy,
  type of construction, location of property, floor
  area, height and number of stories.
• 2 Review the building for conformity with
  occupancy requirements
• 3 Review the building for conformity with the
  type of construction requirements
• 4 Review the building for conformity with egress
  requirements
• 5 Review the building for other detailed code
  regulations
• 6 Review the building for conformity with
  structural engineering regulations and
  requirements for materials of construction

A
B
C
D
E
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Classifying the Building
1A Occupancy Classification Determine the
occupancy group that the use of building or
portion thereof most nearly resembles. Compute
the floor area and occupant load of the building
or portion thereof. See appropriate sections in
Chapter 3 for buildings with mixed occupancies.
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Classifying the Building
1B Type of Construction Determine the type of
construction by the materials used and the
fire-resistance of the parts of the building.
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Classifying the Building
1C Location on Property Determine the location
of the building on the site and clearances to
property lines and other buildings from the plot
plan. Determine the fire-resistance requirements
for exterior walls and wall-openings requirements
based on proximity to property.
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Classifying the Building
1D Allowable Floor Area Determine the allowable
floor area of the building. Use basic allowable
floor area (tabular area) based on occupancy
group and type of construction. Determine
allowable floor area of multistory buildings.
Determine allowable increases based on location
on property and installation of an approved
automatic fire-sprinkler system.
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Classifying the Building
1E Height and Number of Stories Compute the
height of the building and determine the number
of stories. Determine the maximum height and
number of stories permitted based on occupancy
group and type of construction. Determine
allowable height and story increase based on the
installation of an approved automatic
fire-sprinkler system.
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Code Components
Occupancy Type Projects are almost always
defined based on occupancy type. A client asks a
designer for facility with a defined need. The
use of that facility determines the occupancy
group to which it belongs. Each occupancy group
has specific requirements related to allowable
area, height and means of egress with potential
construction types growing out of these
requirements. The codes are fundamentally use
(occupancy) based. Chapter 3 includes the
definitions about occupancy classification
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Code Components
Construction Type Construction types are
categorized with regard to their resistance to
fire in structural applications. Construction
type gives some indication about the amount of
time available for evacuation. (wood, steel,
reinforced concrete). More resistant construction
types are allowed to have more occupants, larger
area, and more stories. Rule of thumb occupancy
quantities and construction costs will both
decrease with building type from Type I to Type
V. Chapter 6 and Table 601 gives a synopsis of
the minimum fire requirements of each main
construction element
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Code Components
Building or Floor Area After one knows the
occupancy group and construction type, it is
important to establish the permissible area for
each floor, for each use and for the entire
building. Some types of construction are
limited in size based on occupancy and
concentration of people. Allowable height and
areas are tabulated in Table 503. Section 506
shows allowable increases based on location on
the property and allowance for installation of
automatic fire-sprinkler systems.
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Code Components
Exits / Egress Determining egress requirements
and provision of safe means of egress is one of
the most important functions of building
codes. There are specific requirements for size,
spacing and travel distances for all components
such as floor plans, doors, corridors and
stairs. In simple terms a means of egress
consists of three main components an exit
access, an exit and and exit discharge.
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Code Components
Building Separation and Shafts In case of mixed
occupancies, codes require fire-rated partitions
separating the occupancies. Separations may also
be used to allow more area for a particular
occupancy on a single floor in certain types of
construction where otherwise such sizes of use
would not be permitted. Openings between floors
such as for stairs, elevators and mechanical
shafts can allow the passage of smoke, heat and
flames. Hence, codes have requirements based on
occupancy, building type and building height
related to shaft protection. Chapter 7
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Code Components
Fire Protection Fire protection is divided in
two broad categories passive or active
protection. Passive protection is the one built
into the structure, either inherent or added as
part of protective membranes (wood, steel,
reinforced concrete combustible or
non-combustible) Active protection is the one
where the fire causes a reaction in the systems
that serve to combat the fire (e.g., sprinklers).
Code analysis and design often includes
trade-offs between active and passive systems.
to be continued
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Code Components
Fire Protection Standards continued Fire
Resistive Standards Include 1 Structure Hour
Rating Requirements of how long it takes for a
fire to weaken a structural element to the point
of failure. Minimum time for evacuation and
fire-fighting response. 2 Area or Occupancy
Separation Rating Requirements of how long it
will take for a fire to penetrate a wall
partition, floor or roof assembly. 3 Flame
Spread and Smoke Generation Requirements of how
long it takes a fire to move along the surface of
the building and how much and what toxicity of
smoke is generated. Chapters 7 and 8
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Code Components
Fire Extinguishing Systems Fire sprinklers,
standpipes, fire detection and fire-alarm systems
are an integral part of many buildings. Use of
such systems often results in trade-offs for
additional height or area. Trade-offs only apply
when the systems are not otherwise required by
the code. The idea of a trade-off recognizes that
this is a mitigation measure over and above basic
code requirements to achieve the desired level of
safety different from those spelled out in the
code. Chapter 9
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Code Components
Engineering Requirements One of the bases of
codes is structural adequacy of building for both
static loading such as occupants and equipment as
well as dynamic loading such as earthquakes, snow
and wind Chapters 16-18 deal with forces,
inspections and foundations Chapters 19-23 deal
with materials concrete, lightweight materials,
masonry, steel and wood.
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Code Analysis
Every Project, no matter how small , should have
a code analysis performed! Wherever possible
consult with the building department and other
Authorities Having Jurisdiction prior to design.
Do not expect the code official to do the
analysis work for you. Remember, compliance is
the responsibility of the designer, not the code
official. However, codes are subject to
interpretation. So its always in your best
interest to determine what, if any,
interpretations will be needed for a
project. REMEMBER DO NOT TRY AND MEMORIZE PARTS
OF THE CODE!!! As sections change and
interpretations alter meanings, such memorization
is a recipe for future trouble. Clients may
expect you to rattle off code requirements, but
its not in the best interest of project or
client to do so and possibly makesnap code
decisions. DO NOT PROCEED ON MEMORY OR ANALOGY
FROM OTHER JOBS! Remember where to look up
information and check your decisions each time
you apply them. Even seasoned code professionals
use the index to locate familiar phrases and
locations of information, especially since items
are often relocated as the code evolves.