That certain document entitled "California Residential Code, 2025 Edition," which adopts by reference the International Residential Code, 2024 Edition, as published by the California Building Standards Commission and the International Code Council (excluding Chapter 1, Division II, R309), including Appendix J of the 2025 Edition of the California Building Code, are hereby adopted with local amendments and provisions of this Chapter of the Santa Monica Municipal Code, as the Residential Code of the City of Santa Monica.
(Added by Ord. No. 2328CCS § 13, adopted 11/9/10; amended by Ord. No. 2445CCS § 13, adopted 11/12/13; Ord. No. 2527CCS § 5, adopted 11/22/16; Ord. No. 2623CCS § 7, adopted 10/22/19; Ord. No. 2727CCS § 7, adopted 10/25/22; Ord. No. 2831CCS, 10/14/2025)
Notwithstanding any provisions of the 2025 California Residential Code, 2025 California Building Standards Code, State Housing Law or other codes adopted by any Chapter in Article 8 of the Municipal Code to the contrary, the following local amendments shall apply.
(Added by Ord. No. 2328CCS § 13, adopted 11/9/10; amended by Ord. No. 2445CCS § 14, adopted 11/12/13; Ord. No. 2527CCS § 5, adopted 11/22/16; Ord. No. 2623CCS § 7, adopted 10/22/19; Ord. No. 2727CCS § 7, adopted 10/25/22; Ord. No. 2831CCS, 10/14/2025)
(a) 
Slopes Steeper than 33-1/3 Percent. Add Section R301.1.5 to the California Residential Code to read as follows:
R301.1.4 Seismic Design Provisions for Buildings Constructed On or Into Slopes Steeper Than One Unit Vertical In Three Units Horizontal (33.3 Percent Slope). The design and construction of new buildings and additions to existing buildings when constructed on or into slopes steeper than one unit vertical in three units horizontal (33.3 percent slope) shall comply with Section 1613.6 of the California Building Code.
(b) 
Irregular Buildings. Amend Items 1, 3, and 5 of Section R301.2.2.2.6 to the California Residential Code to read as follows:
R301.2.2.2.6.
1.
Shear wall or braced wall offsets out of plane. Conditions where exterior shear wall lines or braced wall panels are not in one plane vertically from the foundation to the uppermost story in which they are required.
3.
Shear wall or braced wall offsets in plane. Conditions where the end of a braced wall panel occurs over an opening in the wall below.
5.
Floor level offset. Conditions where portions of a floor level are vertically offset.
(c) 
Application. Amend Section R501.2 of the California Residential Code to read as follows:
R501.2 Requirements. Floor construction shall be capable of accommodating all loads in accordance with Section 301 and of transmitting the resulting loads to the supporting structural elements. Mechanical or plumbing fixtures and equipment shall be attached (or anchored) to the structure in accordance with Section R301.2.2.11.
(d) 
Equipment Anchorage. Section R301.2.2.11 is added to Chapter 3 of the California Residential Code to read as follows:
R301.2.2.11 Anchorage of Mechanical, Electrical, or Plumbing Components and Equipment. Mechanical, electrical, or plumbing components and equipment shall be anchored to the structure. Anchorage of the components and equipment shall be designed to resist loads in accordance with the International Building Code and ASCE 7, except where the component is positively attached to the structure and flexible connections are provided between the component and associated ductwork, piping, and conduit; and either:
1.
The component weighs 400 lb. (1,780 N) or less and has a center of mass located 4 ft. (1.22 m) or less above the supporting structure; or
2.
The component weighs 20 lb. (89 N) or less or, in the case of a distributed system, 5 lb./ft. (73 N/m) or less.
(e) 
Openings in Horizontal Diaphragms. Add Section R503.2.4 to Chapter 5 of the California Residential Code to read as follows:
R503.2.4 Openings in Horizontal Diaphragms. Openings in horizontal diaphragms with a dimension perpendicular to the joist that is greater than 4 feet (1.2 m) shall be constructed in accordance with Figure R503.2.4.
Figure R503.2.4
Openings in Horizontal Diaphragms
a.
Blockings shall be provided beyond headers.
b.
Metal ties not less than 0.058 inch [1.47 mm (16 galvanized gage)] by 1.5 inches (38 mm) wide with eight 16d common nails on each side of the header-joist intersection. The metal ties shall have a minimum yield of 33,000 psi (227 MPa).
c.
Openings in diaphragms shall be further limited in accordance with Section R301.2.2.6.
(f) 
Bracing Requirement. Amend Table R602.10.3(3) of the California Residential Code to read as follows:
For SI: 1 inch = 25.4 mm, 1 foot = 305 mm, 1 pound per square foot = 0.0479 kPa.
a.
Linear interpolation shall be permitted.
b.
Wall bracing lengths are based on a soil site class "D." Interpolation of bracing length between the SDS values associated with the Seismic Design Categories shall be permitted when a site-specific SDS value is determined in accordance with Section 1613.2 of the California Building Code.
c.
Where the braced wall line length is greater than 50 feet, braced wall lines shall be permitted to be divided into shorter segments having lengths of 50 feet or less and the amount of bracing within each segment shall be in accordance with this table.
d.
Method LIB shall have gypsum board fastened to at least one side with nails or screws per Table R602.3(1) for exterior sheathing or Table R702.3.5 for interior gypsum board. Spacing of fasteners at panel edges shall not exceed 8 inches.
e.
Method CS-SFB does not apply in Seismic Design Categories D0, D1, and D2.
f.
Methods GB and PCP braced wall panel h/w ratio shall not exceed 1:1 in SDC D0, D1, or D2. Methods DWB, SFB, PBS, and HPS are not permitted in SDC D0, D1, or D2.
(g) 
Bracing Methods. Amend Table R602.10.4 of the California Residential Code to read as follows:
For SI: 1 inch = 25.4 mm, 1 foot = 305 mm, 1 degree = 0.0175 rad, 1 pound per square foot = 47.8 N/m2, 1 mile per hour = 0.447 m/s.
a.
Adhesive attachment of wall sheathing, including Method GB, shall not be permitted in Seismic Design Categories C, D0, D1, and D2.
b.
Applies to panels next to garage door opening when supporting gable end wall or roof load only. May only be used on one wall of the garage. In Seismic Design Categories D0, D1, and D2, roof covering dead load may not exceed 3 psf.
c.
Garage openings adjacent to a Method CS-G panel shall be provided with a header in accordance with Table R502.5(1). A full height clear opening shall not be permitted adjacent to a Method CS-G panel.
d.
Method CS-SFB does not apply in Seismic Design Categories D0, D1, and D2 and in areas where the wind speed exceeds 100 mph.
e.
Method applies to detached one- and two-family dwellings in Seismic Design Categories D0 through D2 only.
f.
Methods GB and PCP braced wall panel h/w ratio shall not exceed 1:1 in SDC D0, D1, or D2. Methods LIB, DWB, SFB, PBS, HPS, and PFG are not permitted in SDC D0, D1, or D2.
g.
Use of staples in braced wall panels shall be prohibited in SDC D0, D1, or D2.
(h) 
Alternate Braced Wall Panel. Amend Figure R602.10.6.1 of the California Residential Code to read as follows:
FIGURE R602.10.6.1
METHOD ABW — ALTERNATE BRACED WALL PANEL
(i) 
Portal Frame. Amend Figure R602.10.6.2 of the California Residential Code to read as follows:
FIGURE R602.10.6.2
METHOD PFH-PORTAL FRAME WITH HOLD-DOWNS AT DETACHED GARAGE DOOR OPENINGS
(j) 
Minimum Length of Braced Wall Panels. Table R602.10.5 of the California Residential Code is amended to read as follows:
TABLE R602.10.5
a.
Linear interpolation shall be permitted.
b.
Use the actual length where it is greater than or equal to the minimum length.
c.
Maximum header height for PFH is 10 feet in accordance with Figure R602.10.6.2, but wall height shall be permitted to be increased to 12 feet with pony wall.
d.
Maximum header height for PFG is 10 feet in accordance with Figure R602.10.6.3, but wall height shall be permitted to be increased to 12 feet with pony wall.
e.
Maximum header height for CS-PF is 10 feet in accordance with Figure R602.10.6.4, but wall height shall be permitted to be increased to 12 feet with pony wall.
(k) 
Braced Wall Panel. Section R602.10.2.3 of the California Residential Code is amended to read as follows:
R602.10.2.3 Minimum Number of Braced Wall Panels. Braced wall lines with a length of 16 feet (4,877 mm) or less shall have a minimum of two braced wall panels of any length or one braced wall panel equal to 48 inches (1,219 mm) or more. Braced wall lines greater than 16 feet (4,877 mm) shall have a minimum of two braced wall panels. In Seismic Design Category D0, D1, or D2, no braced wall panel shall have a contributing length less than 48 inches in length or as required in Section R602.10.3, whichever is greater.
(l) 
Method CS-PF. Amend Figure R602.10.6.4 of the California Residential Code to read as follows:
FIGURE R602.10.6.4
METHOD CS-PF-CONTINUOUSLY SHEATHED PORTAL FRAME PANEL CONSTRUCTION
FRONT ELEVATION SECTION
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm
(m) 
Additional Requirements. Add Section R803.2.4 to Chapter 8 of the California Residential Code to read as follows:
R803.2.4 Openings in Horizontal Diaphragms. Openings in horizontal diaphragms shall conform with Section R503.2.4.
(n) 
Parapet Walls. Section R606.4.4 of the California Residential Code is amended to read as follows:
R606.4.4 Parapet Walls. Unreinforced solid masonry parapet walls shall not be less than 8 inches (203 mm) thick and their height shall not exceed four times their thickness. Unreinforced hollow unit masonry parapet walls shall be not less than 8 inches (203 mm) thick, and their height shall not exceed three times their thickness. Masonry parapet walls in areas subject to wind loads of 30 pounds per square foot (1.44 kPa) or located in Seismic Design Category D0, D1, or D2, or on townhouses in Seismic Design Category C shall be reinforced in accordance with Section R606.12.
(o) 
Masonry Elements. Section R606.12.2.2.3 of the California Residential Code is amended to read as follows:
R606.12.2.2.3 Reinforcement Requirements for Masonry Elements. Masonry elements listed in Section R606.12.2.2.2 shall be reinforced in either the horizontal or vertical direction as shown in Figure R606.11(23) and in accordance with the following:
1.
Horizontal reinforcement. Horizontal joint reinforcement shall consist of at least one No. 4 bar spaced not more than 48 inches (1,219 mm). Horizontal reinforcement shall be provided within 16 inches (406 mm) of the top and bottom of these masonry elements.
2.
Vertical reinforcement. Vertical reinforcement shall consist of at least one No. 4 bar spaced not more than 48 inches (1,219 mm). Vertical reinforcement shall be within 8 inches (203 mm) of the ends of masonry walls.
(Added by Ord. No. 2328CCS § 13, adopted 11/9/10; amended by Ord. No. 2445CCS § 16, adopted 11/12/13; Ord. No. 2527CCS § 5, adopted 11/22/16; Ord. No. 2623CCS § 7, adopted 10/22/19; Ord. No. 2727CCS § 7, adopted 10/25/22; Ord. No. 2831CCS, 10/14/2025)
(a) 
Foundation Application. Amend Section R401.1 of the California Residential Code to read as follows:
R401.1 Application. The provisions of this chapter shall control the design and construction of the foundation and foundation spaces for all buildings. In addition to the provisions of this chapter, the design and construction of foundations in areas prone to flooding as established by Table R301.2(1) shall meet the provisions of Section R322. Wood foundations shall be designed and installed in accordance with AWC PWF.
Exception: The provisions of this chapter shall be permitted to be used for wood foundations only in the following situations:
1. 
In buildings that have no more than two floors and a roof.
2. 
When interior basement and foundation walls are constructed at intervals not exceeding 50 feet (15,240 mm).
Wood foundations in Seismic Design Category D0, D1, or D2 shall not be permitted.
Exception: In non-occupied, single-story, detached storage sheds and similar uses other than carport or garage, provided the gross floor area does not exceed 200 square feet, the plate height does not exceed 12 feet in height above the grade plane at any point, and the maximum roof projection does not exceed 24 inches.
(b) 
Continuous Footings. Sections R403.1.2, R403.1.3.6 and R403.1.5 of the California Residential Code are amended to read as follows:
R403.1.2 Continuous Footing in Seismic Design Categories D0, D1, or D2. Exterior walls of buildings located in Seismic Design Categories D0, D1, and D2 shall be supported by continuous solid or fully grouted masonry or concrete footings. All required interior braced wall panels in buildings located in Seismic Design Categories D0, D1, and D2 shall be supported on continuous foundations.
R403.1.3.6 Isolated Concrete Footings. In detached one- and two-family dwellings located in Seismic Design Category A, B, or C, that are three stories or less in height, and constructed with stud bearing walls, isolated plain concrete footings supporting columns or pedestals are permitted.
R403.1.5 Slope. The top surface of footings shall be level. The bottom surface of footings shall be permitted to have a slope not exceeding one unit vertical in 10 units horizontal (10 percent slope). Footings shall be stepped where it is necessary to change the elevation of the top surface of the footing or where the surface of the ground slopes more than one unit vertical in 10 units horizontal (10 percent slope).
For structures located in Seismic Design Categories D0, D1, or D2, stepped footings shall be reinforced with four No. 4 rebar. Two bars shall be placed at the top and bottom of the footings as shown in Figure R403.1.5.
FIGURE R403.1.5
STEPPED FOOTING
(c) 
Wood Foundation Walls. Amend Section R404.2 of the California Residential Code to read as follows:
R404.2 Wood Foundation Walls. Wood foundation walls shall be constructed in accordance with the provisions of Sections R404.2.1 through R404.2.6 and with the details show in figures R403.1(2) and R403.1(3). Wood foundation walls shall not be used for structures located in Seismic Design Category D0, D1 or D2.
(Added by Ord. No. 2328CCS § 13, adopted 11/9/10; amended by Ord. No. 2445CCS § 17, adopted 11/12/13; Ord. No. 2527CCS § 5, adopted 11/22/16; Ord. No. 2623CCS § 7, adopted 10/22/19; Ord. No. 2727CCS § 7, adopted 10/25/22)
(a) 
Vertical Reinforcing. Amend Section R1001.3.1 of the California Residential Code to read as follows:
R1001.3.1 Vertical Reinforcing. For chimneys up to 40 inches (1,016 mm) wide, four No. 4 continuous vertical bars adequately anchored into the concrete foundation shall be placed between wythes of solid masonry or within the cells of hollow unit masonry and grouted in accordance with Section R606. Grout shall be prevented from bonding with the flue liner so that the flue liner is free to move with thermal expansion. For chimneys more than 40 inches (1,016 mm) wide, two additional No. 4 vertical bars adequately anchored into the concrete foundation shall be provided for each additional flue incorporated into the chimney or for each additional 40 inches (1,016 mm) in width or fraction thereof.
(Added by Ord. No. 2328CCS § 13, adopted 11/9/10; amended by Ord. No. 2445CCS § 18, adopted 11/12/13; Ord. No. 2527CCS § 5, adopted 11/22/16; Ord. No. 2623CCS § 7, adopted 10/22/19; Ord. No. 2727CCS § 7, adopted 10/25/22; Ord. No. 2831CCS, 10/14/2025)
(a) 
Fastener Schedule. Amend Lines 20, 21, 24 and 34-37 of Table R602.3(1) of the California Residential Code to read as follows:
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s; 1 ksi = 6.895 MPa.
(b) 
Alternate Attachment. Amend footnote "b" of Table R602.3(2) and Section R602.3.2 of the California Residential Code to read as follows:
b.
Staples shall have a minimum crown width of 7/16-inch on diameter except as noted. Use of staples in roof, floor, subfloor, and braced wall panels shall be prohibited in Seismic Design Category D0, D1 or D2.
R602.3.2 Exception: In other than Seismic Design Category D0, D1 or D2, a single top plate used as an alternative to a double top plate shall comply with the following:
1.
The single top plate shall be tied at corners, intersecting walls, and at in-line splices in straight wall lines in accordance with Table R602.3.2.
2.
The rafters or joists shall be centered over the studs with a tolerance of not more than 1 inch (25 mm)
3.
Omission of the top plate is permitted over headers where the headers are adequately tied to adjacent wall sections in accordance with Table R602.3.2.
TABLE R602.3.2
SINGLE TOP-PLATE SPLICE CONNECTION DETAILS
(Added by Ord. No. 2328CCS § 13, adopted 11/9/10; amended by Ord. No. 2445CCS § 20, adopted 11/12/13; Ord. No. 2527CCS § 5, adopted 11/22/16; Ord. No. 2623CCS § 7, adopted 10/22/19; Ord. No. 2727CCS § 7, adopted 10/25/22; Ord. No. 2831CCS, 10/14/2025)