Chapter 3 — Building Planning

Section R301.2 is amended by inserting the following Table R301.2(1).

     The Petaluma Municipal Code is current through Ordinance 2916 NCS, passed December 1, 2025.

Title 17 Building and Construction | Petaluma Municipal Code Page 19 of 170

                Table R301.2(1).  CLIMATIC AND GEOGRAPHIC DESIGN CRITERIA

                                       0       GROUND SNOW LOADo

    WIND DESIGN

        (mph)d                         110

        Topographick               NO

                            NO             Special windl

       Windbornem                    N/A

                                  D2 or E
      SEISMIC DESIGN CATEGORYf          Reference Table R301.2.2.1.1

                                        See mapping tools: www.seismicmaps.org

      SUBJECT TO DAMAGE FROM

        Weatheringa                         Negligible

                                       12 inches             Frost line depthb

        Termitec                         Yes

                                       32 degrees F         WINTER DESIGN TEMPe

       ICE BARRIER UNDERLAYMENT      NO
     REQUIREDh

                                                               Initial NFIP Map Date: March 8, 1974.

                                                               Initial FIRM date: February 15, 1980.

                                            Current Flood Insurance Study dated: February

                                                 19, 2014.
    FLOOD HAZARDSg
                                            Panels 982, 1001, 1002, 1003, and 1004 are dated

                                         October 2, 2015.

                                            Panels 891, 893, 894, and 913 are dated February

                                                 19, 2014.

                                       1 degree F          AIR FREEZING INDEXi

                                       58 degrees F       MEAN ANNUAL TEMPj

     The Petaluma Municipal Code is current through Ordinance 2916 NCS, passed December 1, 2025.

Title 17 Building and Construction | Petaluma Municipal Code Page 20 of 170

                        MANUAL J DESIGN CRITERIAn

                                              Altitude      Indoor        Design       Heating
                     Winter  Summer
  Elevation  Latitude                      correction     design     temperature  temperature
                      heating   cooling
                                               factor    temperature     cooling      diMerence

 87 FT      38       29       90       N/A        68 degrees F.   75 degrees F.   39 degrees F.

            degrees   degrees  degrees

             North.      F.           F.

Cooling Wind Wind Coincident Daily Winter Summer temperature velocity velocity — wet bulb range humidity humidity diMerence heating cooling

 15 degrees F.  N/A       N/A       67 degrees   High. 31   N/A       N/A    —

                                                    F.           degrees

                                                                     F.

 For SI: 1 pound per square foot = 0.0479 kPa, 1 mile per hour = 0.447 m/s.

  a Where weathering requires a higher strength concrete or grade of masonry than necessary to

     satisfy the structural requirements of this code, the frost line depth strength required for

   weathering shall govern.

   The weathering column shall be Zlled in with the weathering index, “negligible,” “moderate” or

    “severe” for concrete as determined from Figure R301.2(4). The grade of masonry units shall be

   determined from ASTM C34, C55, C62, C73, C90, C129, C145, C216 or C652.

  b Where the frost line depth requires deeper footings than indicated in Figure R403.1(1), the frost

     line depth strength required for weathering shall govern. The jurisdiction shall Zll in the frost line

   depth column with the minimum depth of footing below Znish grade.

    c The jurisdiction shall Zll in this part of the table to indicate the need for protection depending

  on whether there has been a history of local subterranean termite damage.

  d The jurisdiction shall Zll in this part of the table with the wind speed from the basic wind speed

  map [Figure R301.2(5)A]. Wind exposure category shall be determined on a site-speciZc basis in

   accordance with Section R301.2.1.4.

   e The outdoor design dry-bulb temperature shall be selected from the columns of 97-1/2

    -percent values for winter from Appendix D of the International Plumbing Code. Deviations from

    the Appendix D temperatures shall be permitted to re[ect local climates or local weather

    experience as determined by the building o\cial. [Also see Figure R301.2(1).]

     The Petaluma Municipal Code is current through Ordinance 2916 NCS, passed December 1, 2025.

Title 17 Building and Construction | Petaluma Municipal Code Page 21 of 170

      f The jurisdiction shall Zll in this part of the table with the seismic design category determined

   from Section R301.2.2.1.

   g The jurisdiction shall Zll in this part of the table with (a) the date of the jurisdiction’s entry into

    the National Flood Insurance Program (date of adoption of the Zrst code or ordinance for

  management of [ood hazard areas), (b) the date(s) of the Flood Insurance Study and (c) the panel

  numbers and dates of the currently e]ective FIRMs and FBFMs or other [ood hazard map

   adopted by the authority having jurisdiction, as amended.

h In accordance with Sections R905.1.2, R905.4.3.1, R905.5.3.1, R905.6.3.1, R905.7.3.1 and

    R905.8.3.1, where there has been a history of local damage from the e]ects of ice damming, the

     jurisdiction shall Zll in this part of the table with “YES.” Otherwise, the jurisdiction shall Zll in this

    part of the table with “NO.”

         i The jurisdiction shall Zll in this part of the table with the 100-year return period air freezing

    index (BF-days) from Figure R403.3(2) or from the 100-year (99 percent) value on the National

    Climatic Data Center data table “Air Freezing Index-USA Method (Base 32°F).”

         j The jurisdiction shall Zll in this part of the table with the mean annual temperature from the

    National Climatic Data Center data table “Air Freezing Index-USA Method (Base 32°F).”

  k In accordance with Section R301.2.1.5, where there is local historical data documenting

     structural damage to buildings due to topographic wind speed-up e]ects, the jurisdiction shall Zll

     in this part of the table with “YES.” Otherwise, the jurisdiction shall indicate “NO” in this part of the

     table.

         l In accordance with Figure R301.2(5)A, where there is local historical data documenting unusual

   wind conditions, the jurisdiction shall Zll in this part of the table with “YES” and identify any

    speciZc requirements. Otherwise, the jurisdiction shall indicate “NO” in this part of the table.

m In accordance with Section R301.2.1.2 the jurisdiction shall indicate the wind-borne debris

   wind zone(s). Otherwise, the jurisdiction shall indicate “NO” in this part of the table.

  n The jurisdiction shall Zll in these sections of the table to establish the design criteria using Table

   1a or 1b from ACCA Manual J or established criteria determined by the jurisdiction.

  o The jurisdiction shall Zll in this section of the table using the Ground Snow Loads in Figure

    R301.2(6).

Section R309.1 is amended, with the exceptions replaced as follows:

R309.1 Townhouse automatic Kre sprinkler systems. An automatic residential Zre sprinkler system

 shall be installed in townhouses.

Exceptions:

     The Petaluma Municipal Code is current through Ordinance 2916 NCS, passed December 1, 2025.

Title 17 Building and Construction | Petaluma Municipal Code Page 22 of 170

 1. Accessory Dwelling Unit, provided that all of the following are met: