Index of Sections

Code Plain English

338B.1 General.

Changing the occupancy of an existing building to commercially/ industrially-oriented JLWQ, Group F, Division 7 Occupancy, or to a residentially-oriented Group R, Division 7 or 8 Occupancy shall be considered a change in use and such buildings shall comply with the applicable requirements in this code including the fire, life safety, structural, and seismic requirements.

338B.1 General.

Change of Use is an important concept in the Building Code. Essentially any project or any portion of a building whose use is deemed to be changing must be brought into compliance with all current codes, i.e. this code, unless otherwise noted.

1) For Group F-7 or R-7 Occupancies in existing buildings minimum seismic requirements may be met if the building substantially conforms, or is altered to conform, to 75% of current CBC [California Building Code] Chapter 16 seismic and wind load design standards.

Unreinforced masonry (URM) bearing wall buildings in-lieu of the above design standards may comply with the current Uniform Code of Building Conservation (UCBC) Appendix Chapter 1. Concrete tilt-up and non-ductile concrete framed buildings that conform to the above standards will still be subject to any future seismic upgrade regulations for these types of buildings unless these buildings conform, or are altered to conform, to current code requirements.

Upgrading a building to today’s code can be onerous. In order to ease this burden, certain exceptions have been made:

Seismic retrofit of any existing building to JLWQ only needs to come up to 75% of normal code standards. This is generally significantly less expensive than a full upgrade.

As is the case in all cities in California, Oakland’s unreinforced masonry buildings (URM’s) are subject to "mandatory measures" –such as roof parapet bracing and connection of floor and roof membranes to exterior walls– which would take precedence over this exception, although normally a 75% upgrade would exceed mandatory, if not so-called "voluntary," measures and therefore govern. It is anticipated that tilt-up and non-ductile concrete framed buildings may come under similar regulations to URM’s, and this exception addresses that eventuality.

2) The occupancy of a story of an existing building or portion of the building may be changed to a Group F, Division 7 Occupancy or a Group R, Division 7 Occupancy without requiring that the entire building comply with all the requirements of this code if all of the following conditions are present or provided: THE FOLLOWING CAN BE A VERY HELPFUL CODE SECTION IN THE RIGHT SITUATION.
A change of use, and its attendant global code upgrade (including seismic) may be avoided altogether if all of the following conditions are met:
2.1 No more than 10% of the floor area of the entire building or of an individual story is or will become designated residential area and no more than ten residents are accommodated on an individual story of the building pursuant to Section 334B.2.2;

2.1 Not more than 10% of the building will –in the aggregate–or of any individual story become "designated residential area," the official name for the living portions of live/work units. Under this building code interpretation, the minimum size of a live/work unit is 660 sq. ft. and the minimum size work area of a unit is 67%, leaving, in this example, 220 square feet for minimum "designated residential area", or living area.

The limitation of 10% "of an individual story" is an important one and,--alas, an onerous one. It means that in a building with an 11,000 square foot floor plate, only 1,100 square feet of that building could be designated residential area, which, if divided by the minimum 220 square feet would mean five units. Unless those units are about 2000 square feet each, another use will have to fill the rest of the floor.

The other half of this sub-section states "no more than ten residents on an individual floor". By the above calculations this would be 15 two-person units each containing 220 square feet of residential space, giving us a total of 1100 square feet of residential area on a floor. An 11,000 square foot building containing less than five live/work units per floor with 220-square foot living portions would not be a change of use. This exception is aimed at those who want to convert only a part of their building to live/work and leave the rest in its former commercial or industrial occupancy, but it can also work for projects with large work spaces and small living portions.

2.2 The existing building, its use, its appendages, and/or its structural system is not declared an unsafe building or structure pursuant to this code or considered unsafe pursuant to other regulations; 2.2 Since the original adoption of this code in 1996, the Oakland Department Building Services) has extended this section to further define what is meant by "declared an unsafe structure." At the discretion of the Building Official (Head of Building Services or another official, like a plan checker), a structural analysis prepared by a structural engineer (at applicant’s expense) would be required.
To summarize, you’re probably OK here as long as you can convince Building Services that your building isn’t unsafe or subject to collapse when "the big one" hits.
2.3 The entire building is made to conform with all the minimum standards for existing buildings in Chapter 4 of the current Uniform Code for Building Conservation; 2.3 The Minimum Standards for Existing Buildings from the UCBC were written to establish a baseline for officials evaluating buildings as they stand, mostly in terms of whether they conform to the intent of today’s codes, tempered with some common sense. Your architect will want to study this UCBC chapter.
HINT: this chapter consists of a concise summary of many building code "hot spots" and is worth reading.

2.4 Other than for work required to comply with the current UCBC pursuant to 2.3 above, additions, alterations, and repairs shall comply with current code; and

2.5 The designated work area and designated residential area of each individual JLWQ comply with the requirements of this chapter.

2.4 Any work you do perform on the building has to conform with the code, including the live/work interpretation. While somewhat redundant, what this means is that new work still has to comply with code, but that the kind of upgrades normally required by a Change of Use would not be necessary.

To repeat, if you can meet all of the requirements of 338B.2, your project is not a change of use, and only needs to meet minimum standards, which do not normally include a seismic retrofit.

HINT: If you meet all of the above standards except the requirement that the building contains not more than 10 residents per floor (i.e. five units), you may be able to break the building down into multiples of ten occupants using an Area Separation Wall (keeping in mind that the smaller buildings' aggregate live portions cannot exceed 10% or 10% of an individual story). For purposes of the Building Code, an area separation wall creates separate buildings on either side of it. It must extend–without horizontal jogs–from foundation to 30’’ above the roof (in the form of a parapet, unless a parapet exemption is seecured). It is a fire wall with a minimum of a two-hour rating, depending on the building’s construction type, but it can have protected openings such as fire-rated doors. Area separation walls (as a tool to break the buildings down into multiple buildings ) are useful for other purposes, such as dealing with maximum allowable area (see UBC Section 504). Note that separate buildings created by area separation walls must have independent required means of egress unless an AMR is secured.