4-0-9 Factory-Built Housing Permits

Establishes a procedure for permitting and inspecting Factory-Built Housing on private property. This policy also clarifies the submittal requirements and fees for Factory-Built Housing.

Factory-Built Housing is a type of residential housing where the components are built in a factory then shipped to a jobsite for assembly. The components can vary from individual wall panels to 500+ square foot modules. Interior finishes can vary from completely finished at the factory to all finishes installed on site. The same holds true for exterior finishes. Often structures built on-site, such as decks, garages, or porches, are attached to the factory-built components. Once assembled, there is no difference between Factory-Built Housing and a site-built residential structure. Both are under the jurisdiction of the County of Sonoma.

The same building codes and the same permitting process apply to both Factory-Built Housing and site-built residential structures with one exception: plan check fees are not charged for portions of the structure that are Factory-Built Housing. Plan check fees will be charged for portions of the structure that are site built. Building permit fees, which cover inspections, are charged regardless of construction type.

Manufactured Homes are different than Factory-Built Housing and area addressed in Policy Number 4-0-10 Placement of Manufactured Homes on Private Property (PDF).

• California Health and Safety Code, Division 13, Part 6
• California Code of Regulations, Title 25, Division 1, Chapter 3,  Subchapter 1

1. Factory-Built Housing: a residential building, dwelling unit, or an individual dwelling room or combination of rooms thereof or building component, assembly, or system manufactured in such a manner that all concealed parts or processes of manufacture cannot be inspected before installation at the building site without disassembly, damage, or destruction of the part, which is either wholly manufactured or is in substantial part manufactured at an offsite location to be wholly or partially assembled onsite in accordance with building standards published in the State Building Standards Code. A permanent foundation is required. Once constructed on site, Factory Built Housing is a permanent dwelling unit. Factory-Built Housing does not include Manufactured homes.
2. Manufactured Home: See Permit Sonoma Policy 4-0-10 Placement of Manufactured Homes on Private Property (PDF)
3. Design Approval Agency: A private organization meeting the requirements of the Department of Housing and Community Development regulations to perform evaluation and approval of Factory-Built Housing plans and specifications which may or may not include foundations, stick-built components of the dwelling and/or roof trusses.

1. GRD-002 Grading Permit Questionnaire (PDF)

1. Procedure for Intake

   1. All plans for Factory-Built Housing shall comply with the State of California requirements for such. These requirements can be found in the “Factory-Built Housing Handbook for City and County Building Department.” This publication is available upon request from the California Department of Housing and Community Development or by going online to: www.hcd.ca.gov/codes/fbh
   2. Plans for Factory-Built Housing shall be stamped by a California Department of Housing and Community Development approved Design Approval Agency on each page. These plans shall be included in the overall plans that are submitted in the Building Permit application.
   3. Plans uploaded for permitting shall clearly identify and delineate the site-built and Factory-Built Housing elements and plan sheet(s), on each individual page and on the plan Cover Sheet and Sheet Index.
   4. Plans or supporting documents uploaded at the time of application must include a clear scope of what is to be done on-site in order to facilitate on-site inspections.
   5. Supporting documents uploaded at the time of application must include the Design Approval Agency approved installation instructions.
   6. The “sub type” will be SNEW or other relating to a single family dwelling e.g. S2NW, SNW2, SREP. The “Class Code” will be a 101 thru 105.
   7. All Factory-Built Housing structures are residential structures only (R occupancy per California Building Code).
   8. Green Building Checklist is required for all non- Factory-Built Housing components i.e. site, foundations, paints, glues…Green Building Plan Check fees will be an adjusted fee at Fifty percent (50%) of the current Permit Sonoma fee schedule.
   9. Clearance from all required Permit Sonoma divisions and Emergency Services.
   10. Plan check fees are not charged for the Factory-Built Housing components. Plan check fees are charged for site-built components.
   11. Components that are not stamped by the Design Approval Agency will be charged full Plan Check fees per the current Permit Sonoma fee schedule.
   12. School Fees and other development impact fees shall apply per current fee schedule.

2. Procedure for Issuance

   1. Upon submittal approval by the Permit Sonoma Plan Check Division (per the “Factory-Built Housing Handbook for City and County Building Departments”) and clearance from all other required divisions, Permit Technicians shall assess fees as follows.
   2. Electrical, Plumbing and Mechanical fees shall be assessed based on the total square footage of the residential structure.
   3. Green Building Inspection fees will be an adjusted fee at fifty percent (50%) of the current Permit Sonoma fee schedule.
   4. Two hours of processing fees, charged at the plan check rate, shall be assessed to each Factory-Built Housing permit for compliance review of the submittal documents and digital approval of the plan sets and applicable supporting documents.
   5. All applicable “Development Impact” fees shall be assessed typical of any new residential structure.
   6. Upon payment of fees and proof of School fees paid the Building Permit shall be issued.

3. Inspection Procedure

   1. Permit Sonoma Building Inspectors shall inspect the on-site Factory-Built Housing assembly and installation in the same manner that is normal for any other site-constructed residential structure. Building Inspectors shall:
      1. Verify the presence of the Department of Housing and Community Development Insignia of Approval on each Factory-Built Housing unit or building component.
      2. Inspect all aspects of the non-Factory-Built Housing components (e.g. foundations, garages, decks).
      3. Verify special inspections are performed if required.
      4. Verify assembly and installation is compliant with the plans and the approved installation instructions.
      5. Verify all required Life/Safety aspects of the California Building Code are met including accessibility requirements when applicable.
      6. Verify compliance with Green Building checklist.
      7. Verify compliance with the California Energy Code requirements.

Not applicable.

Approved By: Tennis Wick, Director

Reviewed By: Department Manager:  ______________

Reviewed By: County Counsel:  ______________

Lead Author:  Bryan Waters, Senior Engineer