Index of Sections

Code Plain English

340B.1 General.

Group F-7 or 8 Occupancy JLWQ shall conform to code requirements for F-1 Occupancies and Group R-7 or 8 Occupancies shall conform to code requirements for R-1 Occupancies as to construction, height and allowable area pursuant to Chapter 3, Chapter 5, Chapter 6, and to related code requirements and to the specific requirements herein.

340B.1 General.

These are technical details which your architect can best address, but the establish the "default building code occupancies which apply to work/live (F=manufacturing) and to live/work (R=residential), which are appropriate to their predominant uses.


For Group F-7 or R-7 Occupancies the following allternatives may be used:

1. Where one-hour fire-resistive construction is required, floors in existing buildings constructed with valid permits may be accepted which have the separation limited to the installation of materials approved for the underside of a one-hour fire-resistive floor/ceiling assembly when the existing flooring system is air-tight and equivalent to a minimum nominal 3/4" thick wood floor.


Normally, one-hour construction is required between live/work units and between units and corridors. This exception relaxes the rated "floor-ceiling assembly" requirement such that existing construction will often suffice, or the addition of a layer of 5/8" type 'x'gypboard (sheet rock) may be all that is required. Note, however that floor/ceiling assemblies between live/work units must be noise-resistant enough to meet minimum STC 50 and IIC 50 standards.

2. Where one-hour fire-resistive construction is required, walls or ceiling surfaces in existing buildings constructed with valid permits, with wood lath and plaster in good condition or one-half inch thick gypsum wall board may be accepted when approved by the Building Official.

Likewise, existing walls and ceilings will often be permissible under this exception even though they do not strictly meet rated wall assembly standards.

Note: While this exception can be helpful, it does not remove the requirement that wall assemblies between units achieve an STC 50 sound attenuation rating.

In an existing building, an approved automatic sprinkler system, as specified in Chapter 38, may be substituted for one-hour fire-resistive construction, provided such system is not otherwise required throughout the building, including a requirement for sprinklers due to inadequate pressure and flow in the fire hydrants or fire supply that would provide protection to the building.

This is a standard provision in the code allowing a sprinklered building to be considered equivalent to a one-hour rated building if the sprinklers are not otherwise required. Reasons why sprinklers "might otherwise be required" include the facts that:

a) the building contains more than 15 units or

b) the building is 3 stories or higher.

340B.1.1 Unlimited Area.

Section 505.2 is not applicable to commercially/ industrially-oriented F-7 or 9 Occupancy JLWQ except Section 505.2 may be applied if a request in approved form and content for alternate materials, alternate design and methods of construction is submitted to and approved by the Building Official (approval is not guaranteed)

340B.1.1 Unlimited Area.

Typically, certain occupancies and construction types may be allowed to be constucted to unlimited floor area if they meet some very rigorous special criteria. A case would need to be made in an AMR application that a level of safety which meets the intent of the code regarding unlimited area is met by the proposed design. But the mere mention of the AMR route suggests there is latitude for the Chief Building Official.

340B.2 Mixed Occupancies.

Group F-7 or 8 Occupancies shall be separated from other occupancies as for an F-1 Occupancy and Group R-7 or 8 Occupancies as for an R-1 Occupancy with a minimum one-hour fire-resistive occupancy separation to all other occupancies.

340B.2 Mixed Occupancies

Table 3-B in the UBC is a matrix of all of the occupancies regulated by the code. Cross-referencing two adjacent occupancies, i.e. contiguous parts of a building being used for different purposes, one finds a fire rating for the required separation (or 'N' for none). For example, an F-1 occupancy- which must be used for F-7 or F-8 must be separated from an H-3 (Hazardous Occupancy) by a minimum one-hour fire separation, i.e. wall or floor ceiling assembly. However, 340B.2 also states that ALL live/work shall be separated from all other occupancies by a minimum one-hour assembly.

340B.3 Special Provision.

Walls and floors separating individual Group F-7 or 8 and R-7 or 8 JLWQ from other F-7 Occupancy spaces shall be not less than one-hour fire-resistive construction.

Storage or laundry rooms that are used in common by tenants of individual F-7 or 8 and Group R-7 or 8 Occupancy JLWQ shall be separated from the rest of the building by not less than one-hour fire-resistive occupancy separation.

340B.3 Special Provision.

As is required in all multi-family residential construction (apartments, condos, etc.), live/work units must be separated from each other (and from rated corridors) by a minimum one-hour rated wall or floor/ceiling assembly.

As is similarly required in residential, common storage or laundry rooms require similar separation from the rest of the building.

340B.4 Exceptions to Table No. 6-A.

Exceptions to Table No. 6-A relating to fire-resistive requirements for types of construction applies to individual spaces of Group F, Division 7 or8 Occupancy pursuant to Section 601.5 including provisions for hotels and apartments pursuant to Section 601.5.2.2. Exceptions to TableNo. 6-A shall apply to individual spaces of Group R-7 or 8 Occupancies pursuant to Section 601.5.2.2.

340B.4 Exceptions to Table No. 6-A.

This means in general that interior and non-load bearing partitions inside of units may be constructed of a lesser rating construction than the building in general. This is particularly true of Type V and Type III buildings, whise unit interiors may be of woodframe with 1/2" sheet rock or other non-combustible facing.