In California all jurisdictional authorities that issue building permits, excluding charter cities, are required to enforce the California Building Standards Code. The current state code is known as the 2001 Building Standards Code and it is based on the latest edition of the model codes. Thus, the California Building Code is based on the 1997 Uniform Building Code, the California Mechanical Code is based on the 2000 Uniform Mechanical Code, the California Plumbing Code is based on the 2000 Uniform Building Code and the California Electrical Code is based on the 1999 National Electrical Code.

In addition to state amendments to the model codes, jurisdictional authorities may also develop local amendments, when deemed necessary. As required by law, Rohnert Park has made findings based on local climatic, geologic and topographical conditions that allows for the adoption of a number of local code amendments. The local amendments to the model codes are considered necessary primarily because of the existence of unusual and deleterious soil conditions. The following is a description of the City's local code amendments.

Building Code

• Section 502 amended - Illuminated street addresses. Subsection 502.1 is added and shall read as follows: "Except buildings which are considered as a minor accessory structure to another structure, all buildings shall have street numbers placed thereon which will be automatically illuminated during night-time hours. The street numbers shall be placed on the front portion of the building closest to the street or driveway and shall be sized so as to be easily read from a vehicle in the street or driveway in front of the building." (Ord. 611§1, 1996).
• Section 1506.3 amended - Roof drainage. Sub-section 1506.3.1 is added and shall read as follows: "All buildings of Group R Occupancy shall include a concrete landing at the exterior of garage side doors. The landing area shall be a minimum of nine sq. ft. (3X3). Group R and U structures shall include rain gutters, downspouts, rain leaders and splash blocks throughout. (Ord. 611§1, 1996).
• Section 1815.1, Division III amended - Buildings utilizing slab on grade construction. Subsection 1815.2 is added and shall read as follows: " Unless conforming to Section 1815, Division I in its entirety, and other than pre- or post tensioned slabs and engineered pier and grade beam foundations systems, buildings utilizing slab on grade construction shall be constructed on a building pad consisting of a minimum of thirty inches of engineered non-expansive fill material meeting the requirements of Table 1 below. The building pad area to receive the engineered non-expansive fill shall include an area at least five feet beyond the outside edge of the building foundation. The building pad area shall be over excavated to the proper depth and the grade scarified to a minimum depth of eight inches and shall be moisture conditioned and re-compacted to a minimum of ninety percent over optimum. The engineered non-expansive fill shall be placed in lifts not exceeding eight inches, brought to near optimum moisture content and compacted to a minimum of ninety percent of maximum dry density at or within two percent of the optimum moisture content. The depth of the engineered non-expansive fill shall be increased as necessary to maintain a minimum of twelve inches of the engineered non-expansive fill material under all footings."
• Subsection 1815.3 is added and shall read as follows: "Except for residential additions of 500 sq. ft. or less and Group U buildings of 500 sq. ft. or less, all foundation designs shall reference a current site specific soils investigation report." (Ord. 611§1, 1996)

• Table 1

  Non-expansive Fill Requirements
  Plasticity Index	less than 13
  Liquid limit	less than 50
  Percent Soil Passing #200 Sieve	between 5% & 45%
  Maximum Aggregate Size	3 inches
  Maximum Dry Density	as determined by ASTM-D1557 test procedures (Ord. 611§1, 1996)

   

• 15.08.050 Section 1900.4.4, Division I amended - Slab reinforcement Subsection 1900.4.4.1 is added and shall read as follows: "All concrete slabs, except sidewalks shall have a minimum reinforcement of #3 rebar placed 18" on center and each way. Reinforcement shall be placed on suitably sized concrete cubes, or similar material approved by the building official, so as to suspend the reinforcement mid plane in the slab. All exterior concrete slabs shall have weakened plane joints at a maximum of 10 ft. intervals each way" (Ord. 611§1, 1996) 15.08.050 - 15.08.080
• Subsection 1900.4.4.2 is added and shall read as follows: "All concrete slabs except sidewalks shall have a minimum sand or approved rock base cushion of not less than four inches in thickness placed immediately below the slab."
• Subsection 1900.4.4.3 is added and shall read as follows: "Except in Group U Occupancies, building slabs shall be protected from the entrance of ground water to the slab area by a moisture barrier. The moisture barrier may consist of 15 lb. Felt paper, lapped no less than six inches and thoroughly mopped with hot asphalt, plastic membrane of not less than 6 mil, lapped no less than six inches, or other materials approved by the building official."
• Title of Chapter 22, Division IV amended - Seismic Provisions for Structural Steel Buildings. The title of Chapter 22, Division IV is amended so as to read "Based on Seismic Provisions for Structural Steel Buildings, of the American Institute of Steel Construction, Part I and III, April, 1997. (Ord. 611§1, 1996).
• 15.08.070 Table 25-G amended - Gypsum board, horizontal requirements. Table 25-G is amended to read under thickness of gypsum wallboard 1/2", Horizontal, Maximum spacing of Framing Member - 24", Perpendicular: NP (Ord. 611§1, 1996).

  Electrical

• Table 300-5 amended - Minimum cover requirements. Table300-5 is amended by deleting reference to "Rigid Metal Conduit" and "Intermediate Metal Conduit". (Ord. 611 §1, 1996: Ord. 559 §1, 1992).
• Article 348-1 amended - Minimum cover requirements. Article348-1 is amended to read as follows: "Metal conduit and electrical metallic tubing shall not be used in the following conditions:

  1. below ground

  Plumbing

• 15.20.020 Sections 301.1.1 & 604.1 amended - Materials. A sentence is added to Sections 301.1.1 and 604.1 and shall read as follows: "All underground service supply lines shall be of non-metallic material consisting of either polyethylene, minimum class 160 or Poly Vinyl Chloride (PVC), minimum schedule 40. Metallic materials may be used when suitable protection, approved by the building official, is provided." (Ord. 611 §1, 1996).
• Appendix Chapters added. Appendix Chapter A, Sizing Water Supply, Appendix Chapter B, Notes on Combination Waste & Vent Systems, Appendix Chapter C, Reference Standards, Appendix Chapter D, Sizing Storm-Water Systems and Appendix Chapter I, Installation Standards, shall be considered as part of the incorporation of the Code as reference in Section No. 15.20.010. (Ord. 611 §1, 1996).

  Mechanical Code

• 15.24.020 Section 607 amended - Use of under floor space as supply plenum. Section 607 of the Code is hereby amended to read as follows: " Use of under floor space as a supply plenum for heating purposes shall not be permitted." (Ord. 611 §1, 1996: Ord 559 §1, 1992).