3 Use and Occupancy

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Lecture 3 Codes Ermal Shpuza
3 Use and Occupancy
Occupancy group classifications trigger specific
requirements for the allowable area and height of
a building, for means of egress, as well as for
the type of construction used. The IBC
requirements are fundamentally occupancy based.
Most of broad sets of code criteria are derived
from the basic classification by occupancy. The
building official is directed by the code to
classify all building or portions of the building
into occupancy groups. The classification uses
the language classified in the group which the
occupancy most nearly resembles, according to the
fire safety and relative hazard involved. Code
provisions have been developed based on
fire-safety and relative hazard performance data
according to different occupancies.
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Occupancy Classifications
Occupancy type results from the programmatic
requirements given to the designer. Code
requirements, as a result, follow from the number
of occupants and the hazards to their safety from
external and internal factors, since the code
looks into the property protection alongside life
safety concerns. Hazards are assessed relative
to their impact on adjacent properties and by
adjacent buildings as well as impact on
occupants. Nevertheless, the responsibility for
the protection of adjacent properties falls upon
the building in consideration. Considerations for
occupancy classification include How many
people Are there assembly areas Are people awake
or asleep Are people using alcohol Are people
undergoing medical treatment Are people free to
move or are they restrained. Hazardous
occupancies are addresses separately
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Occupancy Classifications
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Incidental Use Areas
Uses or occupancies that are incidental to the
main occupancy are not considered to have enough
impact to warrant their classification as a mixed
occupancy. The structure or portion that regards
the classification into one of the occupancy
groups is dealt with in 302.1 When the
occupancy of a building does contain one or more
incidental use areas as defined in Table 302.1.1,
the areas are considered part of the main
occupancy but require fire-resistance-rated
separations from the rest of the occupancy
according to the requirements of the table.
Incidental areas are not applicable to dwelling
units.
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Incidental Use Areas
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Accessory Use Areas
In cases when the occupancy contains a distinctly
different accessory use that takes lt10 of the
area of any floor of the building or less than
the height or area allowed by Table 503, the
accessory use need not be separated from the
primary occupancy. Exceptions exist for
hazardous uses or when required by 302.1.1 as an
incidental use area.
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Mixed Occupancies
In cases when a building has a mix of occupancies
that are distinct or extensive enough as separate
occupancies, each use is considered a separate
and distinct occupancy. The mix of occupancies is
addressed in one of the two ways 1 Separate
Uses An occupancy separation with a
fire-resistance rating as defined by Table
302.3.2 need to be provided between separates
uses. 2 Nonseparated Uses The entire building
is regulated according to the most restrictive of
the height, area and fire protection requirements
for each of the multiple occupancies.
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Mixed Occupancies
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Assembly Group (A)
These uses bring large number of people together
in relatively small spaces. Also, what matters
for this classification regards 1) how spaces
are used in relationship to physical features.
2) how spaces are used in relationship to human
behavior. The final assessment is done by the
building official. Categories constitute
examples rather than an exhaustive and definite
list of possible assignments. Group A
occupancies are defined as having gt 50 occupants.
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Groups (A-1) (A-2)
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Groups (A-3)
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Groups (A-4) (A-5)
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Business Group (B)
Office buildings Storage areas, filing do not
constitute a separate occupancy and are
categorized as B Outpatient clinics and
physician offices, even when patients may be
rendered incapable of self-preservation by
anesthesia. Testing and research labs that do
not exceed amounts for hazardous materials are
classified as B Educational facilities for
junior colleges, universities and continuing
education
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Educational Group (E)
These occupancies are used by gt6 people for
classes up to the 12th grade. Uses for daycare
of gt5 children over 2.5 years of age. Those uses
with lt5 children are classified as occupancy R-3
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Factory and Industrial Group (F)
Defined by what they are not and a process of
elimination. F-1 Moderate-Hazard occupancy and
F-2 Low-Hazard occupancy are based on the
analysis of the relative hazards of the
operations in these occupancies and by
determining that they do not fall under the
criteria set for group H F-2 includes
non-combustible materials. Presumes that There
are no public areas The users are familiar with
their surroundings and not the occasional
visitors.
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High Hazard Group (H)
There are two sets of criteria for hazardous
occupancies. The first is related to the hazard
of the materials in use and the quantities of the
materials in use. Groups H1 to H4 fall in this
category. The second relates to the nature of
the use as well as the quantity and nature of
materials. Provided that there are area
limitations, hazardous materials are allowed in
other occupancies.
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Group (H)
Control Areas The other basic concept in the code
provisions for Group H is that of control areas.
This applies both to subdivisions of buildings
classified as H occupancies and to areas where
hazardous materials occur within other
occupancies. 307.2 The control area concept
is based on that hazard levels are mitigated by
passive and/or active fire protection measures.
This regards two primary considerations 1) the
nature of the hazard of the material, 2) the
level of hazard is primarily related to the
quantity of materials with a given area.
Control areas must be separated from one
another by 1-hour fire-barrier walls and floors
having a minimum fire-resistance rating of 2 hrs.
For the 4th and succeeding floors above grade,
fire-barrier walls must have a 2-hrs
fire-resisting rating.
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Group (H)
Control Areas
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Institutional Group (I)
Institutional occupancies are those where people
have special restrictions placed upon them. The
group is subdivided with regard to the ability of
occupants to take care of themselves. Hence,
categories are defines based on Number of
occupants Age Health and personal liberty Whether
they are in the facility during day or night
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Group (I)
I-1 has gt16 people living under supervision in a
residential environment on a 24 hrs basis. The
occupants can respond to emergencies with little
or no assistance from staff. Similar with lt16
people is R-4, with lt5 as R-3. I-2 has gt5
people under supervision on 24 hrs basis.
Occupants cannot respond to emergencies
unassisted. Hospitals, nursing homes. I-3 has
gt5 people under restraint or security on a 24 hrs
basis. Prisons, detention centers, mental
hospitals I-4 has gt5 people under supervision on
lt24 hrs basis. Similar with lt5 people fall in R-3.
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Mercantile Group (M)
Most retail facilities no matter what they sell,
fall in this occupancy. This occupancy group
includes incidental storage of up to 10 of the
total area. Storage larger than 10 classifies
them as Group S. There are limits to the
quantities of hazardous materials that may be
stored in mercantile occupancies without being
classified as Group H.
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Residental Group (R)
Include typical housing units, distinguished
mainly by the total number of occupants and the
number of days occupants sleep in the
facility. R-1 Occupants sleep lt30 days, hence
they are not familiar with the surroundings.
Hotels. R-2 Occupants are permanent, gt30 days
in gt2 dwelling units. Dormitories, long-term
boarding homes. R-3 Permanent, gt30 days,
defined as not meeting criteria for groups R-1,
R-2, or Group I. Single family residences and
duplexes. R-4 Occupancies used for residential
care or assisted living gt5 and lt16 people. Is
used instead of Group I.
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Storage Group (S)
Storage facilities for materials with quantities
or characteristics not considered hazardous
enough to be classified as Group H are classified
as Group S. S-1 includes Moderate-Hazard
Occupancies S-2 includes Low-Hazard Occupancies
(non-combustible materials)
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Utility and Miscellan. Group (U)
This group includes incidental buildings of an
accessory nature. These structures are typically
unoccupied except for short times. They are
typically separated from other uses and
subservient to other uses. The group contains
also items that are not buildings such as fences
and retaining walls.
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Cases
Case 1 Office building 17,000 sf, 2 stories,
8,500 sf per floor, reinforced concrete
structure, brick walls, unprotected, no
sprinklers. What is the occupancy
classification ? What is the maximum allowable
area per floor ? Case 2 Office building
30,000 sf, single story, with a 3,000 sf seminar
room, with a 2,250 sf storage, unprotected, no
sprinklers. What is the occupancy
classification ? What is the required
separation of occupancies ? What modification
would avoid the separation of occupancies
?
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Cases
Case 3 Apparel retail boutique, one story, plan
100x50, storage 200 sf, steel construction
protected, no automatic sprinklers. What is the
occupancy classification ? What is the
required separation between the store and the
storage ? Case 4 Sophomore textile art
studio, 25 students, 8,000 sf, one story, linked
to 3,000 sf storage room containing 220 pounds of
combustible fiber, automatic sprinkler
system. What is the occupancy classification ?
What is the required separation of occupancies
? Record the steps for calculation and
estimation
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Cases
Case 5 Dancing school hall with 45 person
maximum occupancy, next to 3 offices of the
headmaster, secretary and ticketing. What is the
occupancy classification ? What is the
required separation of occupancies ? Case 6
Fireworks fan using one large room of his 3
bedroom apartment for storing 3 cubic feet of
class 4 oxidizer. What is the occupancy
classification ? What is the required
separation of occupancies ? Record the steps
for calculation and estimation