The purpose of this technical bulletin is to provide a road map from the building code perspective when proposing a change of occupancy from a commercial, Group B occupancy to a residential, Group R-2 occupancy. Note that buildings that are subject to the California Historic Code may have further exceptions and allowances. Note that the items listed below are intended to be a list of common questions asked regarding change of occupancy from commercial to residential. In addition to this list, all applicable code requirements shall be met in order to obtain a permit.

I. General

The California Existing Building Code (CEBC) sets forth the requirements to change the occupancy of an existing building in Section 506. Per this section, changes of occupancy shall not make the existing building less compliant with this code than the existing building was prior to the change. Per Section 506.1, changes of occupancy are permitted without complying with all of the requirements of the code for the new occupancy provided that the new occupancy is less hazardous than the existing occupancy, based upon use and occupancy.

Due to the nature of a residential occupancy, conversion of commercial office space to residential is determined to be more hazardous as the occupants can be sleeping, can house children and other sensitive populations and occupy the space potentially 24/7 whereas a commercial space is occupied during working hours typically.

II. Egress

1. General: Egress shall comply with the requirements of the current California Building Code (CBC) unless specifically exempted by the CEBC.
2. Stairway Design: Existing stairways need not comply with all requirements in the CBC, Section 1011, where the existing design and construction does not allow for a reduction in pitch or slope. Any new stair or alteration to a stair shall comply with the current CBC for stairway design.
3. Emergency Escape and Rescue Openings: If the new residential occupancy triggers emergency escape and rescue windows per CBC 1031, operable windows shall be provided in accordance with CEBC Section 506.4.

III. Structural Design

The structural design for a change of occupancy building need not comply with all requirements in the CBC, Chapter 16. Compliance shall be in accordance with CEBC Section 506.5 and as follows.

1. Live Loads: Design live loads shall comply with Chapter 16 of the CBC unless the demand-capacity ratio, considering the change of occupancy, is not more than 5% greater than the demand-capacity ratio of the previously approved live loads.
2. Snow and Wind Loads: If the change of occupancy results in a higher risk category, the design should be in accordance with CBC Sections 1608 and 1609 unless the area of the new occupancy is less than 10% of the building area.
3. Seismic Loads: If the change of occupancy results in a higher risk category, the building shall comply with CBC Section 1613 unless one of the following exceptions is met:
   1. The area of the new occupancy is less than 10% of the building area, the occupancy change is not Group S to U and the new occupancy is not a Risk Category IV.
   2. Change of use results in the building being reclassified from a Risk Category I or II to Risk Category III and the seismic coefficient, SDS, is less than 0.33.
   3. Change from a Group S or Group U and there is no change in risk category, reduced seismic forces are permitted.

IV. Accessibility

Accessibility shall comply with CBC Chapter 11A and/or 11B, as applicable. Provide clearly on plans if project is publicly funded or privately funded to determine the applicable accessibility code.

V. Sound Transmission and Noise Ratings

1. Sound transmission requirements for dwelling units, as required in CBC Section 1206, must be complied with for the new design.
2. Noise requirements for projects in the airport influence areas as identified in San Diego Municipal Code, Chapter 13, Article 2, Division 15 or in close proximity to a train, railway or freeway must be complied with for the new design. An acoustical analysis report would be required to be provided.

VI. Fire Protection and Life Safety Systems

1. Fire Sprinklers:
   1. All change of occupancy projects where new Group R fire areas are created must be fully sprinkler protected in accordance with NFPA 13 or NFPA 13R, as applicable.
   2. Sprinklers must be quick response. For existing buildings, this may require replacement of sprinklers.
   3. All new piping must comply with the current NFPA standards, including hanging and bracing.
2. Standpipe Systems: If standpipe systems are required by the CBC, then they must be provided. Existing dry standpipe systems must be converted to wet standpipe systems. Hydro testing requirement.
3. Fire Alarm: A fire alarm system must be provided in accordance with the current CBC.
4. High-rise Buildings: For existing high-rise buildings that are changing occupancy, the need for water storage tanks, fire pumps, generators, and redundant water supplies will be evaluated. It is recommended to submit a preliminary review, per Information Bulletin 513, to determine the requirements for the specific project. Fire command centers in accordance with the current code will be required to be provided.
5. Smoke Control Systems: Buildings with existing smoke control systems and high-rise buildings with no existing smoke control system will need to be evaluated for what is provided and what is needed to comply with current requirements. It is recommended to submit a preliminary review, per Information Bulletin 513, to determine the requirements for the specific project.
6. Emergency Responder Radio Coverage Systems: ERRCS are required, as specified in SDFD policy.

VII. Elevators

1. Elevator Lobbies: If the building does not have elevator lobbies and requires elevator lobbies per the CBC, either elevator lobbies need to be provided per CBC Section 3006.1 or a Request for Alternate Materials, Design or Construction Method or a Code Modification needs to be approved per Information Bulletin 151.
2. Gurney Elevators: If the existing building does not contain a gurney elevator as described in CBC Section 3002.4a and the new occupancy requires a gurney-sized elevator, either a gurney elevator needs to be provided in accordance with this section or a waiver must be approved by the Fire Marshal.

VIII. Water and Sewer Systems

1. Water and sewer capacity fees will be charged per unit. Credit will be provided for existing fixtures to be demolished.
2. The change of occupancy from commercial to residential will most likely require new connections to the City Water and Sewer system. When new connections to the water service are provided, backflows may need to be upgraded to current Public Utility Department requirements.
3. Water submeters need to be provided for all new multiple dwelling unit buildings with 3 or more units per San Diego Municipal Code Chapter 14, Article 7, Division 4.

IX. Electrical Systems

All new electrical work shall comply with the current California Electrical Code (CEC). Note that the following shall also be provided or considered.

1. Electrical calculations shall be provided to verify existing service is sufficient for residential use, per CEC, Section 220, Part III.
2. Arc-fault circuit-interrupter protection is required to be provided, per CEC, Section 210.12.
3. Each residential unit will require a separate panel for access to disconnect circuits, per CEC Section 230.72.C.
4. It is highly recommended to verify with SDG&E if the metering of each residential unit is required.
5. If the building is a high-rise and there is no generator provided, either provide a code-compliant generator or a request for alternate methods and materials must be approved.

X. Calgreen and Energy Code Requirements

The building must comply with the current codes. Change of occupancy is considered an alteration and the requirements for alternations would be applicable.

XI. Fees

1. Plan review and inspection fees will be charged per Information Bulletin 501 as a Tenant Improvement.
2. Change of occupancy from commercial to residential will result in school fees due. See Information Bulletin 146.
3. Water and sewer fees will be charged as applicable to the project.