IBC R use groups plus Mass amendments 2013-03-06SECTION 310
RESIDENTIAL GROUP R
310.1 Residential Group R. Residential Group R includes, among others, the use of a building or structure, or a
portion thereof, for sleeping purposes when not classified as an Institutional Group I or when not regulated by the
International Residential Code in accordance with Section 101.2. Residential occupancies shall include the following:
R-1 Residential occupancies containing sleeping units where the occupants are primarily transient in nature,
including:
Boarding houses (transient)
Hotels (transient)
Motels (transient)
Congregate living facilities (transient) with 10 or fewer occupants are permitted to comply with the construction
requirements for Group R-3.
R-2 Residential occupancies containing sleeping units or more than two dwelling units where the occupants are
primarily permanent in nature, including:
Apartment houses
Boarding houses (nontransient)
Convents
Dormitories
Fraternities and sororities
Hotels (nontransient)
Live/work units
Monasteries
Motels (nontransient)
Vacation timeshare properties
Congregate living facilities with 16 or fewer occupants are permitted to comply with the construction requirements
for Group R-3.
R-3 Residential occupancies where the occupants are primarily permanent in nature and not classified as Group R-1,
R-2, R-4 or I, including:
Buildings that do not contain more than two dwelling units.
Adult care facilities that provide accommodations for five or fewer persons of any age for less than 24 hours.
Child care facilities that provide accommodations for five or fewer persons of any age for less than 24 hours.
Congregate living facilities with 16 or fewer persons.
Adult care and child care facilities that are within a single- family home are permitted to comply with the
International Residential Code.
R-4 Residential occupancies shall include buildings arranged for occupancy as residential care/assisted living facilities
including more than five but not more than 16 occupants, excluding staff.
Group R-4 occupancies shall meet the requirements for construction as defined for Group R-3, except as otherwise
provided for in this code or shall comply with the International Residential Code provided the building is protected
by an automatic sprinkler system installed in accordance with Section 903.2.8.
310.2 Definitions. The following words and terms shall, for the purposes of this section and as used elsewhere in this
code, have the meanings shown herein.
CONGREGATE LIVING FACILITIES. A building or part thereof that contains sleeping units where residents share
bathroom and/or kitchen facilities.
310.2 Add or revise definitions as follows:
CONGREGATE LIVING FACILITIES. A building or part thereof that contains sleeping units where residents share
bathroom and/or kitchen facilities. Such facilities may include exempted facilities noted in M.G.L. c. 140, § 22.
RESIDENTIAL CARE/ASSISTED LIVING FACILITIES. A building or part thereof housing persons, on a 24-hour basis, who
because of age, mental disability or other reasons, live in a supervised residential environment which provides
personal care services. The occupants are capable of responding to an emergency situation without physical
assistance from staff. This classification shall include, but not be limited to, the following: residential board and care
facilities, assisted living facilities, halfway houses, group homes, congregate care facilities, social rehabilitation
facilities, alcohol and drug abuse centers and convalescent facilities.
RESIDENTIAL CARE/ASSISTED LIVING FACILITIES.
Mass Amendments 310.2 Add this last sentence and Note:
Assisted living facilities shall conform with this code and M.G.L. c. 19D as administered by the Executive Office of
Elder Affairs. For building code purposes portions of assisted living residences which are used for any use other than
R Use shall be classified, designed and constructed in accordance for their intended use.
Note. This occupancy includes such facilities regulated by the Department of Mental Health that are in conformance
with the occupant safety requirements of 115 CMR 7.00: Standards for All Services and Supports.
IBC Commentary:
Residential care/assisted living facilities are essentially Group I-1 facilities with a smaller number of occupants.
The same provisions that are applicable to Group I-1 facilities are applicable to residential care/assisted living
facilities (e.g., occupants are there on a 24-hour basis and are capable of responding to an emergency situation
without physical assistance).
R-2: The length of the occupants’ stay plus the arrangement of the facilities provided are the basic factors that
differentiate occupancies classified in Group R-2 from other occupancies in Group R. The occupants of facilities or
areas classified in Group R-2 are primarily nontransient, capable of self-preservation and share their means of egress
in whole or in part with other occupants outside of their sleeping area or dwelling unit. The separation between
dwelling units must, at a minimum, meet the requirements contained in Sections 420, 709.1 and 712.3. Building
types ordinarily classified in Group R-2 include apartments, boarding houses (when the occupants are not transient)
and dormitories [see Figures 310.1(2) and 310.1(3)]. Individual dwelling units in Group R-2 are either rented by the
tenants or owner by the occupants. The code does not make a distinction between either type of tenancy. Residential
condominiums are treated in the code the same as Group R-2 apartments. Such condominiums are based on shared
ownership of a building and related facilities. While an individual owner will have exclusive rights to a certain unit,
the building, the lot the building sits upon, parking, common recreational facilities and similar features are owned in
common by all the owners of individual dwelling units. In most cases condominiums do not establish separate lots
and the walls between units are not setting on lot lines. Another type of shared ownership is referred to as a “co-op,”
short for co-operative. Occasionally a condominium will establish actual lots and lot lines distinguishing individual
ownership. When the dwelling unit is located on a separate parcel of land, lot lines defining the parcel exist and the
requirements for fire separation must be met.
Dormitories are generally associated with university or college campuses for use as student housing, but this is
changing rapidly. Many dormitories are now being built as housing for elderly people who wish to live with other
people their own age and who do not need 24-hour-a-day medical supervision. The only difference between the
dormitory that has just been described and the dormitory found on a college campus is the age of its occupants. If
the elderly people must have 24-hour-a-day medical supervision (i.e., a nurse or doctor on the premises), the building
is no longer considered a residential occupancy but an institutional occupancy and would have to comply with the
applicable provisions of the code for the appropriate Group I occupancy. Similar to Group R-1, individual rooms in
dormitories are sleeping units and are required to be separated from each other by fire partitions and horizontal
assemblies in accordance with Sections 420, 709.1 and 712.3. When college classes are not in session, the rooms in
dormitories are sometimes rented out for periods of less than 30 days to convention attendees and other visitors.
When dormitories undergo this type of transient use, they more closely resemble Group R-1. Buildings containing
dormitories often contain other occupancies, such as cafeterias or dining rooms (Group A-2), recreation rooms
(Group A-3) and office (Group B) or meeting rooms (Group A-3). When this
occurs, the building is considered a mixed occupancy and is subject to the provisions of Section 508 [see Figure
310.1(4)]. Included in the listing of Group R-2 are live/work units. A live/work unit is a dwelling unit or sleeping unit
in which a significant portion of the space includes a nonresidential use operated by the tenant. Reflecting a growing
trend in urban neighborhoods and the reuse of existing buildings, live/work units must comply with the provisions of
Section 419. The intent of the congregate living facility reference is to better define when a congregate living facility
is operating as a single-family home. Blended families are now commonplace and not necessarily defined strictly by
blood or marriage. Small boarding houses, convents, dormitories, fraternities, sororities, monasteries and
nontransient hotels and motels may be small enough to operate as a single-family unit and would be permitted to be
constructed as Group R-3 occupancies as intended by the code. The threshold of 16 persons is consistent with the
results of the most recent census, which has 98 percent of all homes in the U.S. containing less than 16 persons.
R-3: Group R-3 facilities include all detached one and two-family dwellings and multiple (three or more) single-family
dwellings (townhouses) more than three stories in height. Those buildings three or less stories in height are not
classified as Group R-3 and are regulated by the IRC (see Section 101.2). Each pair of dwelling units in multiple single-
family dwellings greater than three stories in height must be separated by fire walls (see Section 706) or by two
exterior walls (see Table 602) in order to be classified as Group R-3. (Duplexes, buildings with two dwelling units,
must be detached from other structures in order to be regulated by the IRC.) A duplex attached to another duplex
would be required to comply with the code and be classified as Group R-2 or R-3, depending on the presence of fire
walls. Buildings that are one- and two-family dwellings and multiple single-family dwellings less than three stories
in height and that contain another occupancy (e.g., Groups B, M, I-4) must be regulated as a mixed occupancy in
accordance with the code and are not required to comply with the provisions of the IRC [see Figures 310.1(5) and
310.1(6)]. Some mixed use dwelling units may qualify as live/work units under Section 419 and be classified as a
Group R-2 occupancy.
In addition, institutional facilities other than hospitals, mental hospitals and detoxification facilities, that
accommodate five or fewer people and all congregate living facilities with no more than 16 nontransient occupants
or no more than 10 transient occupants, are to be classified as Group R-3. Where these small care facilities are
provided as a portion of a private home, the intent of the code is that the requirements would be the same as for a
single-family home. As such, the provisions of the IRC can still be utilized. Note that a Group R-3 occupancy is
permitted to accommodate a maximum of five occupants in residential care or assisted living situations. Above that
number of occupants, the proper classification is R-4. The occupants must be capable of responding to an emergency
situation without physical assistance from staff as permitted in a Group I-1 occupancy or not capable of self-
preservation as required for a Group I-2 occupancy. A facility that accommodates five persons who are “capable of
responding to an emergency situation without physical assistance from staff” and five persons “who are not capable
of self-preservation” cannot be classified as a Group R-3 because the total occupant load of 10 persons exceeds the
permitted maximum of five occupants. The facility is a single occupancy; therefore, the entire facility must be
assumed to be occupied by persons with the most restrictive capability when determining the occupancy
classification. A facility that accommodates 16 or more occupants who are not capable of self-preservation is
a Group I-2 occupancy. Buildings that are classified as Group R-3, while limited in height, are not limited in the
allowable area per floor as indicated in Table 503. All dwelling units must be separated from each other by fire
partitions and horizontal assemblies (in accordance with Sections 420, 709.1 and 712.3) unless required to be
separated by fire walls. See also the provisions and commentary for Section 308.5.1, which allows adult day care of
any size to be a Group R-3 occupancy provided the occupants are capable of responding to an emergency situation
without physical assistance from the staff.
R-4: When a limited number of people who require personal care live in a residential environment, a facility is no
longer classified as Group I-1 but as a residential care/assisted living facility, Group R-4. Ninetyeight percent of
households in the U.S. have less than 16 occupants; thus the limit of 16 would allow equal access for the disabled.
The number of occupants includes those who receive care and is not intended to include staff. A Group R-4 occupancy
is not permitted to include any number of occupants that “are not capable of self-preservation.” If an existing Group
R-4 facility has residents added who are not capable of self-preservation, then the occupancy has changed and a
permit to change the occupancy must be obtained (IBC Interpretation No.16-03). Group R-4 facilities must satisfy the
construction requirements of Group R-3 or shall comply with the requirements of the IRC. Note that the provisions of
the code and IRC shall not be mixed. All of the requirements in the code for Group R-3 shall be followed, or all of the
requirements in the IRC shall be followed. (IBC Interpretation No. 50-07).
MGL 19D, Section 18. (a) Assisted living residences shall not be subject to the provisions of sections twentyfive
B to twenty-five H, inclusive, section fifty-one and sections seventy E to seventy-three B,
inclusive, of chapter one hundred and eleven or the seventh full paragraph of section nine of chapter
forty A of the General Laws.
(b) No person or residential facility offering, providing or arranging for the provision of assistance
with or supervision of instrumental activities of daily living only shall be required to obtain
certification under this chapter or a license pursuant to section seventy-one of chapter one hundred
and eleven of the General Laws.
(c) For the purposes of this chapter, and any other general or special law classifying real estate
property for the purpose of taxation, and notwithstanding the provisions of section twenty-seven C of
chapter twenty-nine of the General Laws, a municipality shall classify the portion of any building
operated as an assisted living residence in the same category as property held or used for human
habitation.
(d) Regardless of the designation of an assisted living residence as a residential, institutional or
other use under any zoning ordinance, assisted living residences certified under this chapter shall
be regarded as residential uses for the purposes of the state building code and shall be so
regarded by the building inspectors of each city and town in the commonwealth.