IBC 304.1 interp.pdf2009 IBC Q&A: Nonstructural Provisions
establishing the total occupant load, the area of the
alley may be disregarded. Table 1004.1.1 states that
for "Bowling centers, allow 5 persons for each lane
including 15 feet of runway, and for additional ar-
eas" use 7 square feet net per person. However, if the
building contains a restaurant or cocktail lounge, the
occupant load in such restaurant or cocktail lounge
areas should be based on 15 square feet net per
person. [3-101
• 1 have been working with a university
• laboratory/classroom building on the local
university campus. This project involves an
eight -story addition (approximately 100,000 square
feet) that will be added onto an existing eight -story
building. Located within this addition is a single large
lecture hall (seating 175 students) along with numer-
ous other offices, teaching labs, research labs and
work/prep areas. The interpretation of occupancy
has been questioned regarding this building. I would
appreciate your interpretation as to the occupancy or
occupancies in which you would place this building.
A• A lecture hall with an occupant load of 175
• would be considered a Group A-3 occupancy
in accordance with Section 303.1. Offices, laborato-
ries and rooms used for educational purposes be-
yond the 12th grade with less than 50 occupants in
any room and similar uses would be considered
Group B occupancies in accordance with Section
304.1. [3-111
• What occupancy group would you designate
• a dance studio for classes with an enrollment
limit of 15 children per class between ages 5 and 15?
The dance room is 40 feet by 60 feet. Recitals will be
held four times a year.
A• The function of this facility would be consid-
• ered an assembly use, falling under the Group
A-3 classification. Exception 1 to Section 303.1 does
permit assembly occupancies to be classified as
Group B (Business) if the total occupant load is less
than 50 persons. Note that, although the indicated
class size may be less than 50, the design occupant
load must reflect a worst case scenario. Because re-
citals usually include an audience sitting in chairs, an
occupant factor of 7 square feet per person (Table
1004.1.1) must be applied to the appropriate area.
This table may be applied on a space by space evalu-
ation, subject to the function of individual spaces in
the dance studio. Note as well that, although the
classes may consist of children, this does not warrant
a Group E occupancy classification. [3-121
Q• In Section 303.1 there are three exceptions to
• the Assembly Occupancy classifications al-
lowing for classification as Group B. Do these excep-
tions stil I apply for tenant spaces that include the sale
of alcoholic beverages? I understand this exception
was based on mom and pop stores, small delis and
small fast-food facilities.
A• We understand your situation involves a
• building intended to be used as a wine tasting
and wine sales establishment. It is a separate building
at a small winery where people can tour the winery
and then stop at this building to sample the wines. If
this building (or in another situation a tenant space in
a larger building) complies with either Exception 1, 2
or 3 of Section 303.1, then it can be classified as a
Group B occupancy. The sale of alcoholic beverages
does not disqualify any business from using the ex-
ceptions to be classified as other than Group A. Fur-
thermore, a use being listed as an example in one of
the Group A divisions does not prevent use of these
exceptions.
Any building or tenant space (including a small
night club, tavern, bar or pool/billiard parlor with al-
coholic services) can be classified as a Business
Group B occupancy. The key, as you have correctly
noted, is how the design occupant load is calculated
and whether it is less than 50 or not. [3-131
SECTION 304
BUSINESS GROUP B
304.1 Business Group B. Business Group B occupancy
includes, among others, the use of a building or struc-
ture, or a portion thereof, for office, professional or ser-
vice -type transactions, including storage of records and
accounts. Business occupancies shall include, but not be
limited to, the following:
Airport traffic control towers
Ambulatory health care facilities
Animal hospitals, kennels and pounds
Banks
Barber and beauty shops
Car wash
Civic administration
Clinic —outpatient
Dry cleaning and laundries: pick-up and delivery
stations and self-service
Educational occupancies for students above the
12th grade
Electronic data processing
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