Note: Ord. 22-1500 was repealed by Ord. 26-1537, 1/27/2026.
Except as provided herein, the 2025 Edition of the California Residential Code, (California Code of Regulations, Title 24, Part 2.5), based upon the 2024 International Residential Code, including Appendix BB (Tiny Houses), BF (Patio Covers), BG (Sound Transmission), and C1 (Swimming Pool Safety Act), is hereby adopted by reference as though fully set forth herein, and shall constitute and is hereby established as the “Downey Building Code.” A copy of the 2025 Edition of the California Residential Code is on file in the Building and Safety Division and the office of the City Clerk for use and examination by the public.
(Added by Ord. 26-1537, 1/27/2026)
Section R301.1.3.2 of the 2025 Edition of the California Residential Code is amended to read as follows:
R301.1.3.2 Woodframe structures. The building official shall require construction documents to be approved and stamped by a California licensed architect or engineer for all dwellings of woodframe construction more than two stories and basement in height located in Seismic Design Category A, B or C. Notwithstanding other sections of law; the law establishing these provisions is found in Business and Professions Code Sections 5537 and 6737.1.
The building official shall require construction documents to be approved and stamped by a California licensed architect or engineer for all dwellings of woodframe construction more than one story in height or with a basement located in Seismic Design Category D0, D1, or D2.
(Added by Ord. 26-1537, 1/27/2026)
Section R301.1.5 is added to Chapter 3 of the 2025 Edition of the California Residential Code to read as follows:
R301.1.5. 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.
(Added by Ord. 26-1537, 1/27/2026)
Items 1, 3, and 5 of Section R301.2.2.6 of the 2025 Edition of the California Residential Code are amended to read as follows:
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
(Added by Ord. 26-1537, 1/27/2026)
Section R301.2.2.11 is added to Chapter 3 of the 2025 Edition 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 California 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.
(Added by Ord. 26-1537, 1/27/2026)
Section R401.1 of the 2025 Edition of the California Residential Code is amended 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 buildings. In addition to the provisions of this chapter, the design and construction of foundations in flood hazard areas as established by Table R301.2 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 root
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.
(Added by Ord. 26-1537, 1/27/2026)
Sections R403.1.2, R403.1.3.6, and R403.1.5 of the 2025 Edition 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, or 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, or 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 not have a slope 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 footings or where the slope of the bottom surface of the footings will exceed one unit vertical in 10 units horizontal (10-percent slope).
For structures assigned to Seismic Design Categories D0, D1, or D2, stepped footings shall be reinforced with four No. 4 rebar. Two bars shall be place at the top and bottom of the footings as shown in Figure R403.1.5.
FIGURE R403.1.5 STEPPED FOOTING
(Added by Ord. 26-1537, 1/27/2026)
Section R404.2 of the 2025 Edition of the California Residential Code is amended 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 shown 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. 26-1537, 1/27/2026)
Section R501.1 of the 2025 Edition of the California Residential Code is amended to read as follows:
R501.1 Application. The provisions of this chapter shall control the design and construction of the floors for buildings, including the floors of attic spaces used to house mechanical or plumbing fixtures and equipment. Mechanical or plumbing fixtures and equipment shall be attached or anchored to the structure in accordance with Section R301.2.2.11.
(Added by Ord. 26-1537, 1/27/2026)
Section R503.2.4 is added to Chapter 5 of the 2025 Edition 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
Notes:
a.
Blackings 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.
(Added by Ord. 26-1537, 1/27/2026)
Items 20, 21, 24, and 34 through 37, inclusive, of Table R602.3(1) of the 2025 Edition of the California Residential Code are amended to read as follows:
TABLE R602.3(1)
FASTENING SCHEDULE
TEM
DESCRIPTION OF BUILDING ELEMENTS
NUMBER AND TYPE OF FASTENERa, b, c
SPACING AND LOCATION
Roof
20k
1” x 6” sheathing to each bearing
3-8d box (2 1/2” x 0.113”); or 2-8d common (2 1/2” x 0.131”); or 2-10d box (3” x 0.128”); or 2 staples, 1” crown, 16 ga., 1 3/4” long
Face nail
21k
1” x 8” and wider sheathing to each bearing
3-8d box (2 1/2” x 0.113”); or 3-8d common (2 1/2” x 0.131”); or 3-10d box (3” x 0.128”); or 3 staples, 1” crown, 16 ga., 1 3/4” long
Face nail
Wider than 1” x 8” 4-8d box (2 1/2” x 0.113”); or 3-8d common (2 1/2” x 0.131”); or 3-10d box (3” x 0.128”); or 4 staples, 1” crown, 16 ga., 1 3/4” long
Floor
24k
1” x 6” subfloor or less to each joist
3-8d box (2 1/2” x 0.113”); or 2-8d common (2 1/2” x 0.131”); or 3-10d box (3” x 0.128”); or 2 staples, 1” crown, 16 ga., 1 3/4” long
Face; nail
Other wall sheathingg
34k
1/2” structural cellulosic fiberboard sheathing
1 1/2” galvanized roofing nail, 7/15” head diameter, or 1 1/4” long 16 ga. staple with 7/16” or 1” crown
3
6
35k
25/32” structural cellulosic fiberboard sheathing
1 3/4” galvanized roofing nail, 7/16” head diameter, or 1 1/2” long 16 ga. staple with 7/16” or 1” crown
3
6
36k
1/2” gypsum sheathingd
1 1/2” galvanized roofing nail; staple galvanized, 1 1/2” long; 1 1/4” screws, Type W or S
7
7
37k
5/8” gypsum sheathingd
1 3/4” galvanized roofing nail; staple galvanized, 1 5/8” long; 1 5/8” screws, Type W or S
7
7
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 0.447 mis; 1 ksi = 6.895 MPa.
k.
Use of staples in braced wall panels shall be prohibited in Seismic Design Category D0, D1, or D2.
(Added by Ord. 26-1537, 1/27/2026)
Footnote “b” of Table R602.3(2) of the 2025 Edition of the California Residential Code is amended 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 braced wall panels shall be prohibited in Seismic Design Category D0, D1, or D2.
(Added by Ord. 26-1537, 1/27/2026)
Exception to Section R602.3.2 and Table R602.3.2 of the 2025 Edition of the California Residential Code are amended to read as follows:
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
CONDITION
TOP-PLATE SPLICE LOCATION
Corners and Intersecting Walls
Butt Joints in Straight Walls
Splice plate size
Minimum nails each side of joint
Splice plate size
Minimum nails each side of joint
Structures in SDC A-C; and in SDC D0, D1, and D2 with braced wall line spacing less than 25 feet
3” x 6” x 0.036” galvanized steel plate or equivalent
(6) 8d box (2 1/2” x 0.113”) nails
3” x 12” x 0.036” galvanized steel plate or equivalent
(12) 8d box (2 1/2” x 0.113”) nails
Structures in SDC D0, D1 and D2 with braced wall line spacing greater than or equal to 25 feet
3” x 8” by 0.036” galvanized steel plate or equivalent
(9) 8d box (2 1/2” x 0.113”) nails
3” x 16” x 0.036” galvanized steel plate or equivalent
(18) 8d box (2 1/2” x 0.113”) nails
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
(Added by Ord. 26-1537, 1/27/2026)
Section R602.10.2.3 of the 2025 Edition 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 not less than 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 not less than two braced wall panels. In Seismic Design Category D0, D1, or D2, no braced wall panel shall a contributing length less than 48 inches in length or as required in Section R602.10.3, whichever is greater.
(Added by Ord. 26-1537, 1/27/2026)
Table R602.10.3(3) of the 2025 Edition of the California Residential Code is amended to read as follows:
TABLE R602.10.3(3)
BRACING REQUIREMENTS BASED ON SEISMIC DESIGN CATEGORY
a. 
Linear interpolation shall be permitted.
b. 
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 not less than one side with nails or screws in accordance with 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. 
Methods PFG and CS-SFB do not apply in Seismic Design Categories D0, D1, or D2.
f. 
Methods PFH, PFG and ABW are only permitted on a single story or a first of two stories.
g. 
Where more than one bracing method is used, mixing methods shall be in accordance with Section R602.10.4.1.
h. 
One- and two-family dwellings in Seismic Design Category D2 exceeding two stories shall be designed in accordance with accepted engineering practice.
i. 
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, HPS, and CS-SFB are not permitted in D0, D1, or D2.
(Added by Ord. 26-1537, 1/27/2026)
Table R602.10.4 of the 2025 Edition of the California Residential Code is amended to read as follows:
TABLE R602.10.4
BRACING METHODS1
TABLE R602.10.4— continued
BRACING METHODS1
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 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, or D2.
b. 
Applies to panels next to garage door opening where supporting gable end wall or roof load only. Shall only be used on one wall of the garage. In Seismic Design Categories D0, D1, or D2, roof covering dead load shall not exceed 3 psf.
c. 
Garage openings adjacent to a Method CS-G panel shall be provided with a header in accordance with Table R602.5(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, or D2.
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 ration 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.
(Added by Ord. 26-1537, 1/27/2026)
Table R602.10.5 of the 2025 Edition of the California Residential Code is amended to read as follows:
TABLE R602.10.5 MINIMUM LENGTH OF BRACED WALL PANELS
METHOD
(See Table R602.10.4)
MINIMUM LENGTHa
(inches)
CONTRIBUTING LENGTH (inches)
Wall Height
8 feet
9 feet
10 feet
11 feet
12 feet
DWB, WSP, SFB, PBS, PCP, HPS, BV-WSP
48
48
48
53
58
Actualb
GB
48
48
48
53
58
Double sided = Actual
Single sided = 0.5 × Actual
LIB
55
62
69
NP
NP
Actualb
ABW
SDC A, B and C, ultimate design wind speed < 140 mph
28
32
34
38
42
48
 
SDC D0, D1 and D2, ultimate design wind speed < 140 mph
32
32
34
NP
NP
CS-G
24
27
30
33
36
Actualb
 
Adjacent clear opening height (inches)
 
 
 
 
 
 
CS-WSP, CS-SFB
˂ 64
24
27
30
33
36
Actualb
68
26
27
30
33
36
72
27
27
30
33
36
76
30
29
30
33
36
80
32
30
30
33
36
84
35
32
32
33
36
88
38
35
33
33
36
92
43
37
35
35
36
96
48
41
38
36
36
100
—
44
40
38
38
104
—
49
43
40
39
108
—
54
46
43
41
112
—
—
50
45
43
116
—
—
55
48
45
120
—
—
60
52
48
124
—
—
—
56
51
128
—
—
—
61
54
132
—
—
—
66
58
136
—
—
—
—
62
140
—
—
—
—
66
144
—
—
—
—
72
METHOD (See Table R602.10.4)
Portal header height
 
8 feet
9 feet
10 feet
11 feet
12 feet
 
PFH
Supporting roof only
24
24
24
Note c
Note c
48
Supporting one story and roof
24
24
24
Note c
Note c
PFG
24
27
30
Note d
Note d
1.5 × Actualb
CS-PF
SDC A, B and C
16
18
20
Note e
Note e
1.5 × Actualb
SDC D0, D1 and D2
24
24
24
Note e
Note e
Actualb
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s.
NP = Not Permitted.
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.
(Added by Ord. 26-1537, 1/27/2026)
Figure R602.10.6.1 of the 2025 Edition of the California Residential Code is amended to read as follows:
FIGURE R602.10.6.1 METHOD ABW-ALTERNATE BRACED WALL PANEL
(Added by Ord. 26-1537, 1/27/2026)
Section R606.4.4 of the 2025 Edition 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.
(Added by Ord. 26-1537, 1/27/2026)
Section R606.12.2.2.3 of the 2025 Edition 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(2) 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. 26-1537, 1/27/2026)
Section R803.2.4 is added to Chapter 8 of the 2025 Edition 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.
(Added by Ord. 26-1537, 1/27/2026)
Section R1001.3.1 of the 2025 Edition of the California Residential Code is amended 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. 26-1537, 1/27/2026)