Mountain View Municipal Code Div. 4 Other Local Amendments

Table R301.2 of the 2025 California Residential Code is amended to read as follows:

TABLE R301.2—CLIMATIC AND GEOGRAPHIC DESIGN CRITERIA

Manual J Design Criteria are replaced with the requirements of the 2025 California Energy Code — Climate Zone 4.

(Ord. No. 9.2025, § 6(Exh. B), 9/9/25.)

Subsection R309.1 of the 2025 California Residential Code is amended to read as follows:

R309.1 Townhouse automatic fire sprinkler systems. An automatic fire sprinkler system shall be installed in new townhouses.

Exceptions:

1. An automatic fire sprinkler system shall not be required where additions or alterations are made to existing townhouses that do not have an automatic fire sprinkler system installed, unless Exceptions 2 or 3 below apply.

2. For existing non-sprinklered townhouses, an approved automatic residential fire sprinkler system shall be required when additions meet one of the following criteria:

a. The building addition(s) are equal to or greater than one hundred percent (100%) of the existing building square footage; or

b. The building addition(s) increase the total building area to be cummulatively over 4,100 square feet.

3. Group S-2 or U occupancies used exclusively for vehicle parking and meeting all of the following conditions:

a. Are noncombustible construction:

b. The maximum building area does not exceed a cummulative of 5,000 square feet:

c. The building structure is open on three (3) or more sides; and

d. There is a minimum of ten (10) feet of separation from existing buildings unless the area is separated by fire walls complying with California Building Code Section 706.

(Ord. No. 9.2025, § 6(Exh. B), 9/9/25.)

Subsection R309.2 of the 2025 California Residential Code is amended to read as follows:

R309.2 One- and two-family dwellings automatic fire sprinkler systems. An automatic fire sprinkler system shall be installed in one- and two-family dwellings.

Exceptions:

1. An automatic fire sprinkler system shall not be required for alterations to existing buildings that are not already provided with a sprinkler system.

2. An accessory dwelling unit (ADU), provided that all of the following are met:

a. The unit meets the definition of an accessory dwelling unit as defined in the Government Code Section 65852.2.

b. The existing primary residence does not have automatic fire sprinklers.

c. The accessory detached dwelling unit does not exceed 1,200 square feet in size.

d. The unit is on the same lot as the primary residence.

3. ADUs shall not be required to provide fire sprinklers if they are not required for the primary residence. The construction of an accessory dwelling unit shall not trigger a requirement for fire sprinklers to be installed in the existing primary dwelling.

4. For existing non-sprinklered one- and two-family dwellings, an approved automatic fire sprinkler system shall be required when additions meet one of the following criteria:

a. Building additions that are equal to or greater than one hundred percent (100%) of the existing building square footage;

b. Building additions that increase the total building area to be cummulatively over 4,100 square feet.

5. Group S-2 or U occupancies used exclusively for vehicle parking and meeting all of the following conditions:

a. Are noncombustible construction;

b. The maximum building area does not exceed a cummulative 5,000 square feet;

c. The building structure is open on three (3) or more sides;

d. A minimum of ten (10) feet of separation from existing buildings unless the area is separated by fire walls complying with California Building Code Section 706.

(Ord. No. 9.2025, § 6(Exh. B), 9/9/25.)

Subsections R403.1.3 through R403.1.3.4, including the title of Figure R403.1.3, of the 2025 California Residential Code are amended to read as follows:

R403.1.3 Footing and stem wall reinforcing in Seismic Design Categories D1and D2. Concrete footings located in Seismic Design Categories D 1 , and D 2 , as established in Table R301.2, shall have minimum reinforcement in accordance with this section and Figure R403.1.3. Reinforcement shall be installed with support and cover in accordance with Section R403.1.3.5. Minimum reinforcement shall consist of at least two (2) contiguous longitudinal reinforcing bars not smaller than No. 4 bars. Bottom reinforcement shall be located a minimum of 3 inches (76 mm) clear from the bottom of the footing.

FIGURE R403.1.3 — REINFORCED CONCRETE FOOTINGS AND MASONRY AND CONCRETE STEM WALLS IN SDC D1, and D2 a, b, c, d, e, f

R403.1.3.1 Concrete stem walls with concrete footings. In Seismic Design Categories D 1 , and D 2 where a construction joint is created between a concrete footing and a concrete stem wall, not fewer than one No. 4 vertical bar shall be installed at not more than 4 feet (1219 mm) on center. The vertical bar shall have a standard hook at the footing end and extend to 3 inches (76 mm) clear of the bottom of the footing and shall have support and cover as specific in Section R403.1.3.5.3 and extend not less than 14 inches (357 mm) into the stem wall. Standard hooks shall comply with Section R608.5.4.5. Not fewer than one No. 4 horizontal bar shall be installed within 12 inches (305 mm) of the top of the stem wall and one No. 4 horizontal bar shall be located 3 to 4 inches (76 mm to 102 mm) from the bottom of the footing.

R403.1.3.2 Masonry stem walls with concrete footings. In Seismic Design Categories D 1 and D 2 where a masonry stem wall is supported on a concrete footing, not fewer than one No. 4 vertical bar shall be installed at not more than 4 feet (1219 mm) on center. The vertical bar shall have a standard hook at the footing end and extend to 3 inches (76 mm) clear of the bottom of the footing and shall have support and cover as specified in Section R403.1.3.5.3 and extend not less than 14 inches (357 mm) into the stem wall. Standard hooks shall comply with Section R608.5.4.5. Not fewer than one No. 4 horizontal bar shall be installed within 12 inches (305 mm) of the top of the stem wall and one No. 4 horizontal bar shall be located 3 to 4 inches (76 mm to 102 mm) from the bottom of the footing. Masonry stem walls shall be solid grouted.

R403.1.3.3 Slabs-on-grade with turned-down footings. In Seismic Design Categories D 1 , and D 2 , slabs-on-ground cast monolithically with turned-down footings shall have not fewer than one No. 4 bar at the top and the bottom of the footing or one No. 5 bar or two No. 4 bars in the middle third of the footing depth.

Where the slab is not cast monolithically with the footing, No. 3 or larger vertical dowels with standards hooks on each end shall be installed at no more than 4 feet (1219 mm) on center in accordance with Figure R403.1.3, Detail 2. Standard hooks shall comply with Section R608.5.4.5.

R403.1.3.4 Interior bearing and braced wall panel footings in Seismic Design Categories D1, and D2. In Seismic Design Categories D 1 , and D 2 , interior footings supporting bearing walls or braced wall panels, and cast monolithically with a slab on grade, shall extend to a depth of not less than 12 inches (305 mm) below the top of the slab.

(Ord. No. 9.2025, § 6(Exh. B), 9/9/25.)

Subsection R403.1.3.5.3 of the 2025 California Residential Code is amended to read as follows:

R403.1.3.5.3 Support and cover. Reinforcement shall be secured in the proper location in the forms with tie wire or other bar support system to prevent displacement during the concrete placement operation. Steel reinforcement in concrete cast against the earth shall have a minimum clear cover of 3 inches (75 mm). Minimum clear cover for reinforcement in concrete cast in removable forms that will be exposed to the earth or weather shall be 1½ inches (38 mm) for No. 5 bars and smaller, and 2 inches (50 mm) for No. 6 bars and larger. For concrete cast in removable forms that will not be exposed to the earth or weather, and for concrete cast in stay-in-place forms, minimum clear cover shall be ¾ inch (19 mm).

(Ord. No. 9.2025, § 6(Exh. B), 9/9/25.)

Subsection R403.1.3.5.4 of the 2025 California Residential Code is amended to read as follows:

R403.1.3.5.4 Lap splices. Vertical and horizontal reinforcement shall be the longest continuous lengths practical. Where splices are necessary in reinforcement, the length of lap splice shall be in accordance with Table R608.5.4(1) and Figure R608.5.4(1). The maximum gap between noncontact parallel bars at a lap splice shall not exceed the smaller of one-fifth the required lap length and 6 inches (152 mm) [see Figure R608.5.4(1)].

(Ord. No. 9.2025, § 6(Exh. B), 9/9/25.)

Subsection R403.1.3.6 of the 2025 California Residential Code is amended to read as follows:

R403.1.3.6 Isolated concrete footings. In detached one- and two-family dwellings that are three stories or less in height and constructed with stud bearing walls, isolated plain concrete footings supporting pedestals are permitted when pedestals support no more than a portion of one floor.

(Ord. No. 9.2025, § 6(Exh. B), 9/9/25.)

Table R602.10.3(3) of the 2025 California Residential Code is amended to add a new footnote "i", as noted in the table header, to read as follows:

MINIMUM TOTAL LENGTH (FEET) OF BRACED WALL PANELS REQUIRED ALONG EACH BRACED WALL LINEa,g,i

i. In Seismic Design Categories D l , and D 2 , Method GB (gypsum board) and BV-WSP (Wood Structural Panels with Stone Masonry) is not permitted; and use of Method PCP (Portland Cement Plaster) is limited to one-story, single-family dwellings and accessory structures.

(Ord. No. 9.2025, § 6(Exh. B), 9/9/25.)