• Welcome to The Building Code Forum

    Your premier resource for building code knowledge.

    This forum remains free to the public thanks to the generous support of our Sawhorse Members and Corporate Sponsors. Their contributions help keep this community thriving and accessible.

    Want enhanced access to expert discussions and exclusive features? Learn more about the benefits here.

    Ready to upgrade? Log in and upgrade now.

non separated uses with an R occupancy

R

retire09

Silver Member
Joined
Feb 19, 2010
Messages
365
Location
Alaska
Can you have a building with B, S-1 and R-1 uses and build to the standard of the R-1 and avoid the 2 hr separations from the B and S-1? (Non separated uses)

The R will still have the minimum 1 hr separations from all other uses and other sleeping rooms but the 2 hr separations would no longer apply. (IBC 420.2)

Also could the sprinklers required by the R occupancy be done throughout the building with a 13R system?
 
Can answer the second one

NO!

Have you looked at this 2009

508.3 Nonseparated occupancies. Buildings or portions of buildings that comply with the provisions of this section shall be considered as nonseparated occupancies.

508.3.1 Occupancy classification. Nonseparated occupancies shall be individually classified in accordance with Section 302.1. The requirements of this code shall apply to each portion of the building based on the occupancy classification of that space except that the most restrictive applicable provisions of Section 403 and Chapter 9 shall apply to the building or portion thereof in which the nonseparated occupancies are located.

508.3.2 Allowable building area and height. The allowable building area and height of the building or portion thereof shall be based on the most restrictive allowances for the occupancy groups under consideration for the type of construction of the building in accordance with Section 503.1.

508.3.3 Separation. No separation is required between nonseparated occupancies.

Exceptions:

1. Group H-2, H-3, H-4 and H-5 occupancies shall be separated from all other occupancies in accordance with Section 508.4.

2. Group I-1, R-1, R-2 and R-3 dwelling units and sleeping units shall be separated from other dwelling or sleeping units and from other occupancies contiguous to them in accordance with the requirements of Section 420.
 
The only occupancy in the building that requires sprinklers is the R.

The building is required to be fully sprinklered.

Would the B and S occupancies, even though not required to be otherwise sprinklered require that the system be a full 13?
 
Yes, 13R is not for non residential

NFPA 13R: Document Scope

1.1* Scope. This standard shall cover the design and installation of automatic sprinkler systems for protection against fire hazards in residential occupancies up to and including four stories in height. 1.1.1 This standard assumes that the sprinkler system shall be designed to protect against a fire originating from a single ignition location.
 
retire09 said:
Can you have a building with B, S-1 and R-1 uses and build to the standard of the R-1 and avoid the 2 hr separations from the B and S-1? (Non separated uses)
Click to expand...
If you use the nonseparated occupancies method, or, if the sum of the the Group B and Group S-1 areas do not exceed 10% of the floor area in which they are located, then they can be considered accessory occupancies and no separation is required.

retire09 said:
Also could the sprinklers required by the R occupancy be done throughout the building with a 13R system?
Click to expand...
It depends. If the Group R-1 is the predominant occupancy and the Groups B and S-1 are incidental to the Group R-1, then a NFPA 13R system is permitted throughout the building, including the Group B and S-1 areas. This is explained in Annex A, Explanatory Material, in the 2010 NFPA 13R (Referenced by the 2012 IBC).
 
RLGA said:
If you use the nonseparated occupancies method, or, if the sum of the the Group B and Group S-1 areas do not exceed 10% of the floor area in which they are located, then they can be considered accessory occupancies and no separation is required.It depends. If the Group R-1 is the predominant occupancy and the Groups B and S-1 are incidental to the Group R-1, then a NFPA 13R system is permitted throughout the building, including the Group B and S-1 areas. This is explained in Annex A, Explanatory Material, in the 2010 NFPA 13R (Referenced by the 2012 IBC).
Click to expand...
Have to read the annex,

appears the accessory is more related to the apartment and areas associated with an apartment, like office, storage rooms, garage or similar, I would not say an actual strip of businesses, or similar.
 
Last edited by a moderator:
cda said:
Have to read the annex, Does it say a per centage? to allow 13R?,
Click to expand...
I have read the annex. There is no percentage indicated, thus making it a subjective interpretation. However, since one of the definitions of 'predominate' means of greater number (per my dictionary), then if the floor area of the Group R-1 exceeds the floor areas of the Groups B and S-1, then I would consider the Group R-1 to be the predominant occupancy. Therefore, a spread of 33% for Group B, 33% for Group S-1, and 34% for Group R-1 would make the Group R-1 the predominant occupancy, even though it is a minor separation.

They also indicate that the other occupancies must be incidental to the predominant occupancy. Thus, the Group B and Group S-1 areas cannot be spaces that do not support the Group R-1 (e.g. leased tenant offices and storage lockers for non occupants of the Group R-1). If the Group B is an admin office and the Group S-1 is a storage room that support the Group R-1, then they would be considered incidental to the predominant occupancy (i.e. Group R-1).
 
RLGA said:
I have read the annex. There is no percentage indicated, thus making it a subjective interpretation. However, since one of the definitions of 'predominate' means of greater number (per my dictionary), then if the floor area of the Group R-1 exceeds the floor areas of the Groups B and S-1, then I would consider the Group R-1 to be the predominant occupancy. Therefore, a spread of 33% for Group B, 33% for Group S-1, and 34% for Group R-1 would make the Group R-1 the predominant occupancy, even though it is a minor separation.They also indicate that the other occupancies must be incidental to the predominant occupancy. Thus, the Group B and Group S-1 areas cannot be spaces that do not support the Group R-1 (e.g. leased tenant offices and storage lockers for non occupants of the Group R-1). If the Group B is an admin office and the Group S-1 is a storage room that support the Group R-1, then they would be considered incidental to the predominant occupancy (i.e. Group R-1).
Click to expand...
Like the clarification. I read that way but would have to be case by case, which I hate.

Thought I was going to have to FedEx my code stretcher to you.

Thanks for the annex reference
 
Incidental uses in the Code are typically very small spaces of uniquely dangerous nature (boiler rooms where equipment ratings exceed 400,000 BTU/hr, etc) and do not get classified separately by use group.

That the other spaces are being classified indicates that they are not incidental as provided for in the Code.

The non-separated approach will work, depending on the sum of the ratios, but the 13R system will not IMHO
 
JBI - The use of 'incidental' in the code (IBC) is different than its use in the standard (NFPA 13R). In the standard, the use of 'incidental' is mentioned only in the Annex. Although the Annex in the NFPA standard is not part of the requirements--which is stated outright at the beginning of the Annex--the explanatory material in the Annex can be used as justification for interpretation. The building/fire official can disallow the use of a NFPA 13R system in the nonresidential areas, even if they are 'incidental' (NFPA 13R usage of the term) to the main residential use, since nothing in the actual requirements explicitly allows it. However, the building/fire official would be going against the intent of the standard, since NFPA has explained the standard's intent in the Annex and may lose if a contrary interpretation is challenged on appeal.
 
The S and B uses are not incidental or accessory to the R. The beak down would be approximately 30%-R, 30%-B and 40%-S. The typical use of the R is sleeping for just a few hours or occasionally over night and are not the same people working in the B and S areas. The S floor area is about 4000sf. The R use will be upstairs over the B with the S on the other side of the wall. I have found nothing that would clearly disallow the 13R system in the building. I have never seen this done but need a code section to prevent it.
 
903.2.8 Group R.

An automatic sprinkler system installed in accordance with Section 903.3 shall be provided throughout all buildings with a Group R fire area.

903.3.1.2 NFPA 13R sprinkler systems.

Automatic sprinkler systems in Group R occupancies up to and including four stories in height shall be permitted to be installed throughout in accordance with NFPA 13R.

(I like NYS language better in 903.3.1.2... Where allowed in buildings of Group R... )

From there, the standard would dictate/limit applicability. 13R is only for Residential Occupancies.

Since the Code requires the system to be installed throughout all buildings with a Group R fire area, the Code has dictated that it must be a full NFPA 13 system. 13R only allows for a limited amount of non-residential space to be protected by a 13R system, beyond that you must upgrade to full 13. (Neither standard provides for a 'mix and match' approach). Regardless of how NFPA uses the term 'incidental', the standard itself contains the limits on applicability. The Code requires a system throughout the building.

Were the Group R on the other side of the fire wall with the B & S sharing a 'building', different story...
 
Since there was no mention of a horizontal assembly requiring a 2 hr. separation in accordance with section 420.3; where does it require a 2 hr. separation other than for separated occupancies in section 508.4?
 
I found a 2009 Fire Code Commentary and it says when the R occupancy is the only use requiring the system, the 13R is allowed in the R areas only and a 13 system is in all other occupancies. So it would be both.

As far as the occupancy separation, I beleive the minimum one hour between the R and the B and S would still apply. The separation between sleeping room could be reduced to 20min due to the sprinkler system.

Am I on the right track?
 
Fast answers make politicians happy (sometimes...), but are rarely accurate.

I'm not sure why the Commentary would suggest violating the Standards, but always remember the commentary is not the Code.
 
retire09 said:
I found a 2009 Fire Code Commentary and it says when the R occupancy is the only use requiring the system, the 13R is allowed in the R areas only and a 13 system is in all other occupancies. So it would be both.As far as the occupancy separation, I beleive the minimum one hour between the R and the B and S would still apply. The separation between sleeping room could be reduced to 20min due to the sprinkler system.

Am I on the right track?
Click to expand...
No you can have a NFPA 13 system in a "R" occupancy such as hotel

Remember also 13 R is normally only good to four stories
 
JBI said:
903.2.8 Group R. An automatic sprinkler system installed in accordance with :Next('./icod_ifc_2012_9_par069.htm')'>Section 903.3 shall be provided throughout all buildings with a Group R fire area.

903.3.1.2 NFPA 13R sprinkler systems.

Automatic sprinkler systems in Group R occupancies up to and including four stories in height shall be permitted to be installed throughout in accordance with NFPA 13R.

(I like NYS language better in 903.3.1.2... Where allowed in buildings of Group R... )

From there, the standard would dictate/limit applicability. 13R is only for Residential Occupancies.

Since the Code requires the system to be installed throughout all buildings with a Group R fire area, the Code has dictated that it must be a full NFPA 13 system. 13R only allows for a limited amount of non-residential space to be protected by a 13R system, beyond that you must upgrade to full 13. (Neither standard provides for a 'mix and match' approach). Regardless of how NFPA uses the term 'incidental', the standard itself contains the limits on applicability. The Code requires a system throughout the building.

Were the Group R on the other side of the fire wall with the B & S sharing a 'building', different story...
Click to expand...
JBI, I don't see where it states in the above that a 13 system is required in all cases. It states that a sprinkler system in accordance with Section 903.3 is required throughout, and the NFPA 13R is a part of that section; therefore it can be used throughout...provided the residential occupancy is predominant and the nonresidential areas are incidental to the Group R.

However, based on what retire09 has provided, a 13R cannot be used, since the Group B and S occupancies are not incidental to the Group R, even though the Group R it is the predominant occupancy. A NFPA 13 system will be required, since a building cannot mix a 13 and 13R system unless a single structure that is separated into distinct and separate "buildings" by fire walls or a horizontal separation per 2012 IBC Section 510.2 (See NFPA video:

). If a fire wall or horizontal separation is provided between the residential occupancies and the nonresidential occupancies, then a 13R system can be used in the residential "building" and a 13 system in the nonresidential "building."If a NFPA 13 system is used, and the residential is not separated from the nonresidential occupancies by fire walls or a horizontal separation as stated above, then the residential portions must be protected with residential or quick-response sprinklers per NFPA 13.
 
You must log in or register to reply here.
Back
Top