Portola Valley Municipal Code Ch. 15.04 Building Code

Footnotes:

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Editor's note— Ord. 2025-454, § 2, adopted Jan. 14, 2026, repealed the former Ch. 15.04, §§ 15.04.010—15.04.030, 15.04.060, 15.04.080, enacted a new Ch. 15.04 as set out herein. The former Ch. 15.04 pertained to similar subject matter and derived from Ord. 2022-447 §§ 1—4, 7, 9 adopted Oct. 26, 2022.

The town's building code is comprised of the following uniform codes:

A. 2025 California Administrative Code (Part 1 of Title 24) California Code of Regulations, California Building Standards Commission; and

B. 2025 California Building Code, Volumes 1 and 2 (Part 2 of Title 24) California Code of Regulations, California Building Standards Commission Based on the 2024 International Building Code (IBC) published by the International Code Council (ICC), with modifications; and

C. 2025 California Residential Code (Part 2.5 of Title 24) California Code of Regulations, California Building Standards Commission and Appendices: Appendix BF: Patio Covers; Appendix BG: Sound Transmission and Appendix CI: Swimming Pool Safety Act, based on the 2024 International Residential Code (IRC) published by the International Code Council, with modifications; and

D. 2025 California Electrical Code (Part 3 of Title 24) California Code of Regulations, California Building Standards Commission Based on the 2023 National Electrical Code (NEC) published by the National Fire Protection Association; and

E. 2025 California Mechanical Code (Part 4 of Title 24) California Code of Regulations, California Building Standards Commission Based on the 2024 Uniform Mechanical Code (UMC) published by the International Association of Plumbing and Mechanical Officials (IAPMO); and

F. 2025 California Plumbing Code (Part 5 of Title 24) California Code of Regulations, California Building Standards Commission based upon the 2024 Uniform Plumbing Code (UPC) published by the International Plumbing and Mechanical Officials (IAPMO) and Appendix K with modifications; and

G. 2025 California Energy Code (Part 6 of Title 24) California Code of Regulations, California Building Standards Commission; and

H. 2025 California Wildland-Urban Interface Code (Part 7 of Title 24) Adopted by the Building Standards Commission with modifications; and

I. 2025 California Historical Building Code (Part 8 of Title 24), California Code of Regulations, California Building Standards Commission; and

J. 2025 California Fire Code (Part 9 of Title 24) California Code of Regulations, California Building Standards Commission Based on the 2024 International Fire Code (IRC) published by the International Code Council; and

K. 2025 California Existing Building Code (Part 10 of Title 24) California Code of Regulations, California Building Standards Commission; and

L. 2025 Green Building Standards Code (Cal Green) (Part 11 of Title 24) California Code of Regulations, California Building Standards Commission with modifications; and

M. 2025 California Referenced Standards Code (Part 12 of Title 24) Adopted by the Building Standards Commission.

(Ord. 2025-454, § 3, 2026)

A. The 2025 California Building Code, Title 24, Part 2, Volume 1 and 2, referred to throughout this Chapter as the "Building Code," is hereby referred to and, except as to additions, deletions and amendments hereinafter described, such code is hereby adopted and made a part hereof, the same as if fully set forth in this section, and shall be the Building Code of the Town. In accordance with California Health and Safety Code Section 17958.7, express findings that modifications to the Building Code are reasonably necessary because of local climatic, geological, or topographical conditions are either already on file with the California Building Standards Commission or will be filed prior to the effective date of the ordinance codified in this section.

B. Subsection 101.1 of the California Building Code is hereby amended to read as follows:

[A] 101.1 Title.

These regulations shall be known as the Building Code of the Town of Portola Valley, hereinafter referred to as "this code".

C. Subsection 105.2 of the California Building Code is hereby amended to read as follows:

[A]

105.2 Work exempt from permit.

Exemptions from permit requirements of this code shall not be deemed to grant authorization for any work to be done in any manner in violation of the provisions of this code or any other laws or ordinances of this jurisdiction. Permits shall not be required for the following:

1. One-story detached accessory building used as a tool or storage shed, playhouse, and similar use provided the floor area does not exceed 120 square feet (11.15 m 2 ). It is permissible that these structures still be regulated by Section 710A, despite exemption from permit.

2. Nonfixed and movable fixtures, cases, racks, counters and partitions not over five feet nine inches (1,753 mm) in height

3. Retaining walls that are not over four feet (1,219 mm) in height measured from the bottom of the footing to the top of the wall, unless supporting a surcharge or impounding Class I, II or III-A Liquids.

4. Water tanks supported directly on grade if the capacity is not greater than 5,000 gallons (18,925 L) and the ratio of height to diameter or width does is not greater than 2:1.

5. Platforms and walks, not more than 30 inches (762 mm) above adjacent grade, and not over any basement or story below and are not part of an accessible route.

6. Painting, papering, tiling, carpeting, cabinets, counter tops and similar finish work.

7. Window awnings in Group R, Division 3 (Single Family Residence), and Group U (Private Garage) Occupancies, supported by an exterior wall that do not project more than 54 inches (1,372 mm) from the exterior wall and do not require additional support.

8. Prefabricated swimming pools accessory to a Group R, Division 3 Occupancy that are less than 24 inches (610 mm) deep, are not greater than 5,000 gallons (18,925 L) and are installed entirely above ground.

9. Swings, temporary sports devices, and other playground equipment accessory to detached one- and two-family dwellings.

D. Subsection 109.6 of the California Building Code is hereby amended to read as follows:

[A]

109.6 Refunds.

The Building Official may authorize refunding of:

1. Any fee paid hereunder, which was erroneously paid or collected.

2. Not more than 80 percent of the permit fee paid when no work has been done under a permit issued in accordance with this code.

3. Not more than 80 percent of the plan review fee paid when an application for a permit for which a plan review fee has been paid is withdrawn or cancelled before any plan reviewing is done.

The Building Official shall not authorize refunding of any fee paid except on written application filed by the original permittee not later than 180 days after the date of the fee payment.

E. Subsection 111.3 of the California Building Code is hereby amended to read as follows:

[A]

111.3 Temporary occupancy.

The building official is authorized to issue a temporary certificate of occupancy before the completion of the entire work covered by the permit, provided that such portion or portions shall be occupied safely. The building official shall set a time period during which the temporary certificate of occupancy is valid. Even if a temporary occupancy permit has been obtained, in no event shall a building be sold or transferred until the final inspection has been signed by the town's building official.

A. Upon request, the town's building official shall provide an applicant with an application for temporary occupancy permit and a list of the town's minimum requirements for temporary occupancy permit. The minimum requirements for temporary occupancy permit shall be developed by the town's building official at their sole discretion.

B. The town's building official may at their sole discretion issue a temporary occupancy permit for the use of a portion or portions of a building if, and only if, the applicant provides a surety deposit in the form of a letter of credit from a savings institution and made payable to the town of Portola Valley or a cashier's check in the amount of ten thousand dollars.

1. Any costs of the town in enforcing the terms of the temporary occupancy permit or removing occupants from the premises shall be deducted from the surety deposit. If the costs to the town exceed the amount of the surety deposit, the applicant shall be responsible for immediately paying the town any deficiency.

2. The town may in its sole discretion require further deposits or bonds, in an amount not to exceed the cost of completion of the project, plus up to twenty percent to cover any costs incurred by the town in completing the project.

C. The duration of a temporary occupancy permit shall not be more than one year from the date of approval of the temporary occupancy permit. Failure to complete the project within the lesser of one year or the time period indicated on the temporary occupancy permit may result in the immediate revocation of the temporary occupancy permit and eviction from the premises.

D. If the project is not completed in the time set forth in the temporary occupancy permit, which in no event shall exceed one year, the applicant shall show cause for the failure to complete the project and submit a schedule for completion. The applicant must show cause and present a schedule to the town's building official within ten days of the expiration of the temporary occupancy permit or no extension or reinstatement of the temporary occupancy permit will be allowed. The town's building official shall have sole discretion whether to revoke or extend the temporary occupancy permit in light of the evidence concerning the failure to complete the project. The town's building official shall have sole discretion as whether or not the revised scheduled is acceptable. Within ten days of the applicant presenting evidence and a revised schedule, the town's building official shall either extend or revoke the temporary occupancy permit.

E. If a temporary occupancy permit is revoked, the utilities will be disconnected from the project and abatement proceeding may occur in accordance with the town's municipal code and local, state and federal rules and regulations.

F. Subsection 113.1 of the California Building Code is hereby amended to read as follows:

[A]

113.1 General.

In order to hear and decide appeals of orders, decisions or determinations made by the building official relative to the application and interpretation of this code, there shall be and is hereby created a board of appeals. The board of appeals shall be the Town Council. The board shall render all findings in writing to the appellant with a duplicate copy to the building official.

G. Subsection 114.4 of the California Building Code is hereby amended to read as follows:

[A]

114.4 Violation penalties.

Any person who commences any work for which a permit is required, such as, but not limited to: grading, demolition, or on a building, structure, electrical, gas, mechanical, fire protection or plumbing system before obtaining the necessary permits shall be subject to a fee established by fee resolution that shall be in addition to the required permit fees. Double Building Permit Fees will apply at a minimum of $500.00 plus $500.00 fine may be added for each violation (type of construction) where a building permit should have been issued.

H. Subsection 903.2 of the California Building Code is hereby added to read as follows:

903.2 Where required.

An approved automatic sprinkler system in buildings and structures shall be provided in the locations described in 903.2.1 through 903.2.12 and Sections 903.2.14 through 903.2.21.

Exceptions:

1. An approved automatic sprinkler system shall not be required in existing structures where repairs, alterations, additions and additions that include alterations are made to unsprinklered, existing buildings when building permit(s) have been issued within any 12-month period that collectively do not exceed more than 50 percent of the existing floor area, 50 percent of the existing wall area or when the combination of the percentages of affected floor area and affected wall area exceeds 50 percent. The following guidance shall be used to calculate these percentages:

a. Calculation of Percentage of Affected Floor Area (PFA): The floor area of any addition, all rooms affected by any addition, and the floor area of all rooms affected by structural changes made in the building, such as walls, columns, beams or girders, floor or ceiling joists and coverings, roof rafters, roof diaphragms, footings, piles or retaining walls or similar components, shall be included in computing the floor areas for applying this section.

b. Calculation of Percentage of Affected Wall Area (PWA): The calculated wall area affected shall include all interior and exterior walls where no studs are proposed to be remain or if some studs remain and/or if the surface of both sides of the studs are proposed to be removed such that one can see through the wall.

c. Calculation of Combination of Percentage of Affected Floor Area (PFA) and Wall Area (PWA): The combination of the percentage of affected floor as described above plus the percentage of wall area as described above (PFA + PWA > 50%).

I. Subsection 1031.2 of the California Building Code is hereby amended to read as follows:

1031.2 Where required.

In addition to the means of egress required by this chapter, emergency escape and rescue openings shall be provided in Group R occupancies.

Basements and sleeping rooms below the fourth story above grade plane shall have not fewer than one emergency escape and rescue opening in accordance with this section. Where basements contain one or more sleeping rooms, an emergency escape and rescue opening shall be required in each sleeping room but shall not be required in adjoining areas of the basement. Such openings shall open directly into a public way or to a yard or court that opens to a public way.

Exceptions:

1. In group R-1 and R-2 occupancies constructed of Type I, Type IIA, Type IIIA or Type IV construction equipped throughout with an approved automatic sprinkler system in accordance with Section 903.3.1.1.

2. Group R-2.1 occupancies meeting the requirements for delayed egress in accordance with Section 1010.2.13 may have operable windows that are breakable in sleeping rooms permanently restricted to a maximum of 4-inch open position.

3. Basements with a ceiling height of less than 80 inches (2,032 mm) shall not be required to have emergency escape and rescue openings.

4. Emergency escape and rescue openings are not required from basements or sleeping rooms that have an exit door or exit access door that opens directly into a public way or to a yard, court or exterior egress balcony that opens to a public way.

5. Basements without habitable spaces and having not more than 200 square feet (18.6 m 2 ) in floor area shall not be required to have emergency escape and rescue openings.

6. Storm shelters are not required to comply with this section where the shelter is constructed in accordance with ICC 500.

J. Section 1405.1 of the California Building Code is hereby amended to read as follows:

1405.1 Combustible exterior wall coverings.

Exterior wall coverings shall be of noncombustible materials.

Exception: Alterations to existing exterior wall coverings that affect less than 10% of the exterior of the building.

K. Section 1505.1 of the California Building Code is hereby amended to read as follows:

[BF] 1505.1 General.

The minimum roof coverings installed on buildings shall be Class A rated tested in accordance with ASTM E108 or UL 790 such as concrete, tile, metal or slate. Wood roof coverings are prohibited.

Exception:

1. Roof covering replacement that affects 25% or less of the building structure.

L. Table 2308.10.1 of section 2308.10 of the California Building Code is hereby amended as follows:

The title of Table 2308.10.1 is amended to read:

Table 2308.10.1 Wall Bracing Requirements

Footnotes are added as follows:

Footnotes "f" and "g" are added to Table 2308.10.1, to read:

f. Methods PBS, HPS, and SFB are not permitted in Seismic Design Categories D or E.

g. Methods GB, DWB and PCP are not permitted in Seismic Design Category E.

(Ord. 2025-454, § 4, 2026)

A. The 2025 California Residential Code, Title 24, Part 2.5, referred to throughout this Chapter as the "Residential Code," is hereby referred to and, except as to additions, deletions and amendments hereinafter described, such code is hereby adopted and made a part hereof, the same as if fully set forth in this section, and shall be the Residential Code of the Town. In accordance with California Health and Safety Code Section 17958.7, express findings that modifications to the Residential Code are reasonably necessary because of local climatic, geological, or topographical conditions are either already on file with the California Building Standards Commission or will be filed prior to the effective date of the ordinance codified in this section.

B. Subsection R101.1 of the California Residential Code is hereby amended to read as follows:

R101.1 Title.

These regulations shall be known as the Residential Code for One- and Two-Family Dwellings of the Town of Portola Valley, hereinafter referred to as "this code".

C. Subsection R105.2 of the California Residential Code is hereby amended to read as follows:

R105.2 Work exempt from permit.

Exemptions from permit requirements of this code shall not be deemed to grant authorization for any work to be done in any manner in violation of the provisions of this code or any other laws or ordinances of this jurisdiction. Permits shall not be required for the following:

1. Other than storm shelters, one-story detached accessory structures, provided the floor area does not exceed 120 square feet (11.15 m 2 ). It is permissible that these structures still be regulated by Part 7 California Wildland-Urban Interface Code, despite exemption from permit.

2. Retaining walls that are not over four feet (1,219 mm) in height measured from the bottom of the footing to the top of the wall, unless supporting a surcharge.

3. Water tanks supported directly upon grade if the capacity does not exceed 5,000 gallons (18,927 L) and the ratio of height to diameter or width does not exceed 2:1.

4. Platforms and walks, not more than 30 inches above grade and not over any basement or story below.

5. Painting, papering, tiling, carpeting, cabinets, counter tops and similar finish work.

6. Window awnings supported by an exterior wall that do not project more than 54 inches (1,372 mm) from the exterior wall and do not require additional support.

7. Prefabricated swimming pools that are less than 24 inches (210 mm) deep. Swings, temporary sports devices, and other playground equipment accessory to detached one- and two-family dwellings.

8. Decks not exceeding 200 square feet (18.58 m 2 ) in area, that are not more than 30 inches (762 mm) above grade at any point, are not attached to a dwelling or townhouse and do not serve the exit door required by Section 318.4.

Electrical:

1. Listed cord-and-plug connected temporary decorative lighting.

2. Reinstallation of attachment plug receptables but not the outlets therefor.

3. Replacement of branch circuit overcurrent devices of the required capacity in the same location.

4. Electrical wiring, devices, appliances, apparatus or equipment operating at less than 25 volts and not capable of supplying more than 50 watts of energy.

5. Minor repair work, including the replacement of lamps or the connection of approved portable electrical equipment to approved permanently installed receptacles.

Gas:

1. Portable heating, cooking or clothes drying appliances.

2. Replacement of any minor part that does not alter approval of equipment or make such equipment unsafe.

3. Portable-fuel-cell appliances that are not connected to a fixed piping system and are not interconnected to a power grid.

Mechanical:

1. Portable heating appliances.

2. Portable ventilation appliances.

3. Portable cooling units.

4. Steam, hot- or chilled-water piping within any heating or cooling equipment regulated by this code.

5. Replacement of any minor part that does not alter approval of equipment or make such equipment unsafe.

6. Portable evaporative coolers.

7. Self-contained refrigeration systems containing 10 pounds (4.54 kg) or less of refrigerant or that are actuated by motors of 1 horsepower (746 W) or less.

8. Portable-fuel-cell appliances that are not connected to a fixed piping system and are not interconnected to a power gride.

Plumbing:

1. The stopping of leaks in drains, water, soil, waste or vent pipe; provided, however, that if any concealed trap, drainpipe, water, soil, waste or vent pipe becomes defective and it becomes necessary to remove and replace the same with new material, such work shall be considered as new work and a permit shall be obtained and inspection made as provided in this code.

2. The clearing of stoppages or the repairing of leaks in pipes, valves or fixtures, and the removal and reinstallation of water closets, provided such repairs do not involve or require the replacement or rearrangement of valves, pipes or fixtures.

D. Subsection R108.5 of the California Residential Code is hereby amended to read as follows:

R108.5 Refunds.

The Building Official may authorize refunding of:

1. Any fee paid hereunder, which was erroneously paid or collected.

2. Not more than 80 percent of the permit fee paid when no work has been done under a permit issued in accordance with this code.

3. Not more than 80 percent of the plan review fee paid when an application for a permit for which a plan review fee has been paid is withdrawn or cancelled before any plan reviewing is done.

The Building Official shall not authorize refunding of any fee paid except on written application filed by the original permittee not later than 180 days after the date of the fee payment.

E. Subsection R110.3 of the California Residential Code is hereby amended to read as follows:

R110.3 Temporary occupancy.

The building official is authorized to issue a temporary certificate of occupancy before the completion of the entire work covered by the permit, provided that such portion or portions shall be occupied safely. The building official shall set a time period during which the temporary certificate of occupancy is valid. Even if a temporary occupancy permit has been obtained, in no event shall a building be sold or transferred until the final inspection has been signed by the town's building official.

A. Upon request, the town's building official shall provide an applicant with an application for temporary occupancy permit and a list of the town's minimum requirements for temporary occupancy permit. The minimum requirements for temporary occupancy permit shall be developed by the town's building official at their sole discretion.

B. The town's building official may at their sole discretion issue a temporary occupancy permit for the use of a portion or portions of a building if, and only if, the applicant provides a surety deposit in the form of a letter of credit from a savings institution and made payable to the town of Portola Valley or a cashier's check in the amount of ten thousand dollars.

1. Any costs of the town in enforcing the terms of the temporary occupancy permit or removing occupants from the premises shall be deducted from the surety deposit. If the costs to the town exceed the amount of the surety deposit, the applicant shall be responsible for immediately paying the town any deficiency.

2. The town may in its sole discretion require further deposits or bonds, in an amount not to exceed the cost of completion of the project, plus up to twenty percent to cover any costs incurred by the town in completing the project.

C. The duration of a temporary occupancy permit shall not be more than one year from the date of approval of the temporary occupancy permit. Failure to complete the project within the lesser of one year or the time period indicated on the temporary occupancy permit may result in the immediate revocation of the temporary occupancy permit and eviction from the premises.

D. If the project is not completed in the time set forth in the temporary occupancy permit, which in no event shall exceed one year, the applicant shall show cause for the failure to complete the project and submit a schedule for completion. The applicant must show cause and present a schedule to the town's building official within ten days of the expiration of the temporary occupancy permit or no extension or reinstatement of the temporary occupancy permit will be allowed. The town's building official shall have sole discretion whether to revoke or extend the temporary occupancy permit in light of the evidence concerning the failure to complete the project. The town's building official shall have sole discretion as whether or not the revised scheduled is acceptable. Within ten days of the applicant presenting evidence and a revised schedule, the town's building official shall either extend or revoke the temporary occupancy permit.

E. If a temporary occupancy permit is revoked, the utilities will be disconnected from the project and abatement proceeding may occur in accordance with the town's municipal code and local, state and federal rules and regulations.

F. Subsection R112.1 of the California Residential Code is hereby amended to read as follows:

R112.1 General.

In order to hear and decide appeals of orders, decisions or determinations made by the building official relative to the application and interpretation of this code, there shall be and is hereby created a board of appeals. The board of appeals shall be the Town Council. The board shall render all findings in writing to the appellant with a duplicate copy to the building official.

G. Subsection R113.4 of the California Residential Code is hereby amended to read as follows:

R113.4 Violation penalties.

Any person who commences any work for which a permit is required, such as, but not limited to: grading, demolition, or on a building, structure, electrical, gas, mechanical, fire protection or plumbing system before obtaining the necessary permits shall be subject to a fee established by fee resolution that shall be in addition to the required permit fees. Double Building Permit Fees will apply at a minimum of $500.00 plus $500.00 fine may be added for each violation (type of construction) where a building permit should have been issued.

H. Subsection R301.2 of the California Residential Code is hereby amended to read as follows:

R301.2 Climatic and geographic design criteria.

Buildings shall be constructed in accordance with the provisions of this code as limited by the provisions of this section. Additional criteria shall be established by the local jurisdiction and set forth in Table R301.2.

CLIMATIC AND GEOGRAPHIC DESIGN CRITERIA

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

a. Weathering may require a higher strength concrete or grade of masonry than necessary to satisfy the structural requirements of this code. The weathering column shall be filled in with the weathering index, "negligible," "moderate" or "severe" for concrete as determined from Figure R301.2(3). The grade of masonry units shall be determined from ASTM C34, C55, C62, C73, C90, C129, C145, 0216 or C652.

b. The frost line depth may require deeper footings than indicated in Figure R403.1(1). The jurisdiction shall fill in the frost line depth column with the minimum depth of footing below finish grade.

c. The jurisdiction shall fill 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 fill in this part of the table with the wind speed from the basic wind speed map [Figure R301.2(4)A]. Wind exposure category shall be determined on a site?specific basis in accordance with Section R301.2.1.4.

e. Temperatures shall be permitted to reflect local climates or local weather experience as determined by the building official.

f. The jurisdiction shall fill in this part of the table with the seismic design category determined from Section R301.2.2.1.

g. The jurisdiction shall fill 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 first code or ordinance for management of flood hazard areas), (b) the date(s) of the Flood Insurance Study and (c) the panel numbers and dates of the currently effective FIRMs and FBFMs or other flood hazard map adopted by the authority having jurisdiction, as amended.

h. In accordance with Sections R905.1.2, R905.4.3.1, 8905.5.3.1, R905.6.3.1, R905.7.3.1 and R905.8.3.1, where there has been a history of local damage from the effects of ice damming, the jurisdiction shall fill in this part of the table with "YES." Otherwise, the jurisdiction shall fill in this part of the table with "NO."

i. The jurisdiction shall fill 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 fill 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 effects, the jurisdiction shall fill 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(4)A, where there is local historical data documenting unusual wind conditions, the jurisdiction shall fill in this part of the table with "YES" and identify any specific requirements, Otherwise, the jurisdiction shall indicate "NO" in this part of the table.

m. In accordance with Section R301.2.1.2.1, 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 fill 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 fill in this section of the allowable stress design table using the Ground Snow Loads in Figure R301.2(3).

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

R309.1 Townhouse automatic fire sprinkler systems.

An automatic fire sprinkler system shall be installed in townhouses.

Exception: An automatic residential fire sprinkler system shall not be required where repairs, additions or alterations are made to existing townhouses that do not have automatic residential fire sprinkler systems installed when building permit(s) have been issued within any 12-month period that do not collectively exceed more than 50 percent of the existing floor area, 50 percent of the existing wall area or 50 percent of the combination of affected floor area and affected wall area percentages. In calculating these percentages, the following guidelines shall apply:

a. Calculation of Percentage of Affected Floor Area (PFA): The floor area of any addition, all rooms affected by any addition, and the floor area of all rooms affected by structural changes made in the building, such as walls, columns, beams or girders, floor or ceiling joists and coverings, roof rafters, roof diaphragms, footings, piles or retaining walls or similar components, shall be included in computing the floor areas for applying this section.

b. Calculation of Percentage of Affected Wall Area (PWA): The calculated wall area affected shall include all interior and exterior walls where no studs are proposed to be remain or if some studs remain and/or if the surface of both sides of the studs are proposed to be removed such that one can see through the wall.

c. Calculation of Combination of Percentage of Affected Floor Area (PFA) and Wall Area (PWA): The combination of the percentage of affected floor as described above plus the percentage of wall area as described above (PFA + PWA < 51%).

J. Subsection R309.1.1 of the California Residential Code is hereby amended to read as follows:

R3091.1 Design and Installation.

Automatic residential fire sprinkler systems for townhouses shall be designed and installed in accordance with section R313 or NFPA 13D.

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

R309.2 One and two-family dwelling automatic fire sprinkler systems.

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

Exceptions:

1. An automatic residential fire sprinkler system shall not be required where repairs, alterations, additions and additions that include alterations to existing buildings for which building permit(s) have been issued within any 12-month period that do not collectively exceed more than 50 percent of the existing floor area, 50 percent of the existing wall area or 50 percent of the combination of affected floor area and affected wall area percentages. In calculating these percentages, the following guidelines shall apply:

a. Calculation of Percentage of Affected Floor Area (PFA): The floor area of any addition, all rooms affected by any addition, and the floor area of all rooms affected by structural changes made in the building, such as walls, columns, beams or girders, floor or ceiling joists and coverings, roof rafters, roof diaphragms, footings, piles or retaining walls or similar components, shall be included in computing the floor areas for applying this section.

b. Calculation of Percentage of Affected Wall Area (PWA): The calculated wall area affected shall include all interior and exterior walls where no studs are proposed to be remain or if some studs remain and/or if the surface of both sides of the studs are proposed to be removed such that one can see through the wall.

c. Calculation of Combination of Percentage of Affected Floor Area (PFA) and Wall Area (PWA): The combination of the percentage of affected floor as described above plus the percentage of wall area as described above (PFA + PWA > 50%).

2. Residential fire sprinkler system shall not be required for an accessory dwelling unit, if all the following are met:

2.1

The unit meets the definition of an Accessory Dwelling Unit as defined in the Government Code section 65852.2

2.2

The existing primary residence does not have automatic fire sprinklers.

2.3

The accessory detached dwelling unit does not exceed 1,200 square feet in size and is located in compliance with the setbacks of the base zoning district at required by the Portola Valley Municipal Code

2.4

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

L. Subsection R309.2.1 of the California Residential Code is hereby amended to read as follows:

R309.2.1 Design and Installation.

Automatic residential fire sprinkler systems shall be designed and installed in accordance with section R309 or NFPA 13D.

M. Subsection R319.1 of the California Residential Code is hereby amended to read as follows:

R319.1 Emergency escape and rescue opening required.

Basements, habitable attics, the room to which a sleeping loft is open, and every sleeping room shall have not less than one operable emergency escape and rescue opening. Where basements contain one or more sleeping rooms, an emergency escape and rescue opening shall be required in each sleeping room. Emergency escape and rescue openings shall open directly into a public way.

Exceptions:

1. Basements with a ceiling height of less than 80 inches (2,032 mm) shall not be required to have emergency escape and rescue openings.

2. Emergency escape and rescue openings are not required from basements or sleeping rooms that have an exit door or exit access door that opens directly into a public way or to a yard, court or exterior egress balcony that opens to a public way.

3. Basements without habitable spaces and having not more than 200 square feet (18.6 m 2 ) in floor area shall not be required to have emergency escape and rescue openings.

4. Storm shelters are not required to comply with this section where the shelter is constructed in accordance with ICC 500.

N. Subsection R319.7 of the California Residential Code is hereby amended to read as follows:

R319.7 Alterations or repairs of existing basement.

New sleeping rooms created in an existing basement shall be provided with emergency escape and rescue opening in accordance with Section 319.1. Other than new sleeping rooms, where existing habitable basements undergo alteration or repairs, an emergency escape and rescue opening is not required.

O. Subsection R319.7.1 of the California Residential Code is hereby deleted.

P. Subsection R330.1 of the California Residential Code is hereby amended to read as follows:

R330.1 General.

Energy storage systems (ESS) shall comply with the provisions of this section.

Exceptions:

1. ESS less than 1 kWh (3.6 megajoules)

Q. Table R602.10.3(3) of subsection R602.10.3 of the California Residential Code is hereby amended as follows:

The title of Table R602.10.3(3) is amended to read:

TABLE R602.10.3(3) i, j Bracing Requirements Based On Seismic Design Category

Footnotes are added as follows:

Footnotes "i" and "j" are added to Table R602.10.3(3), to read:

i. Methods PBS, HPS, SFB and CS-SFB are not permitted in Seismic Design Categories D0, D1, and D2.

j. Methods GB, DWB and PCP are not permitted in Seismic Design Categories D0, D1, and D2 where S1 is greater than or equal to 0.75.

R. Subsection R902.1 of the California Residential Code is hereby amended to read as follows:

R902.1 Roof covering materials.

Roofs shall be covered with materials as set forth in sections 904 and 905. A minimum Class A roofing shall be installed. Class A roofing is required by this section to be listed shall be tested in accordance with UL 790 or ASTM E 108. Wood roof coverings are prohibited.

S. Subsection R902.1.1 of the California Residential Code is hereby amended as follows:

R902.1.1 Roof coverings within fire hazard severity zones or in Wildland-Urban Interface (WUI) areas.

The entire roof covering of every existing structure where more than 25 percent of the total roof area is replaced within any one-year period; where the addition of new roof area exceeds 25 percent of the existing roof area; the entire roof covering of every new building; and any roof covering applied in the alteration, repair or replacement of the roof of every existing structure, shall also comply with Part 7, California Wildland-Urban Interface Code.

T. Subsection R902.1.2 of the California Residential Code is hereby amended as follows:

R902.1.2 Roof coverings in all other areas.

The entire roof covering of every existing structure where more than 25 percent of the total roof area is replaced within any one-year period; where the addition of new roof area exceeds 25 percent of the existing roof area; the entire roof covering of every new building; and any roof covering applied in the alteration, repair or replacement of the roof of every existing structure, shall also comply with Part 7, California Wildland-Urban Interface Code.

U. Subsection R902.2 of the California Residential Code is hereby deleted in its entirety.

(Ord. 2025-454, § 5, 2026)

The 2025 California Electrical Code, Title 24, Part 3, referred to throughout this chapter as the "Electrical Code," is hereby adopted and made a part hereof, the same as if fully set forth in this section, and shall be the Electrical Code of the Town.

(Ord. 2025-454, § 6, 2026)

The 2025 California Mechanical Code, Title 24, Part 4, referred to throughout this chapter as the "Mechanical Code," is hereby adopted and made a part hereof, the same as if fully set forth in this section, and shall be the Mechanical Code of the Town.

(Ord. 2025-454, § 7, 2026)

A. The 2025 California Plumbing Code, Title 24, Part 5, referred to throughout this Chapter as the "Plumbing Code," is hereby adopted and, except as to additions, deletions and amendments hereinafter described, made a part hereof, the same as if fully set forth in this section, and shall be the Plumbing Code of the Town. In accordance with California Health and Safety Code Section 17958.7, express findings that modifications to the Plumbing Code are reasonably necessary because of local climatic, geological, or topographical conditions are either already on file with the California Building Standards Commission or will be filed prior to the effective date of the ordinance codified in this section.

B. Subsection 1211.8 Earthquake Actuated Gas Shutoff Valves, of the California Plumbing Code is hereby adopted.

(Ord. 2025-454, § 8, 2026)

The 2025 California Energy Code, Title 24, Part 6, referred to throughout this Chapter as the "Energy Code," is hereby adopted and made a part hereof, the same as if fully set forth in this section, and shall be the Energy Code of the Town.

(Ord. 2025-454, § 9, 2026)

The 2025 California Historical Building Code, Title 24, Part 8, referred to throughout this Chapter as the "Historical Building Code," is hereby adopted and made a part hereof, the same as if fully set forth in this section, and shall be the Historical Building Code of the Town.

(Ord. 2025-454, § 10, 2026)

The 2025 California Fire Code, Title 24, Part 9, referred to throughout this Chapter as the "Fire Code," is hereby adopted and made a part hereof, the same as if fully set forth in this section, and shall be the Fire Code of the Town.

(Ord. 2025-454, § 11, 2026)

The 2025 California Existing Building Code, Title 24, Part 10, referred to throughout this Chapter as the "Existing Building Code," is hereby adopted and made a part hereof, the same as if fully set forth in this section, and shall be the Existing Building Code of the Town.

(Ord. 2025-454, § 12, 2026)

A. The 2025 California Green Building Standards Code, Title 24, Part 11, referred to throughout this Chapter as the "Green Building Standards Code," is hereby adopted and, except as to additions, deletions and amendments hereinafter described, made a part hereof, the same as if fully set forth in this section, and shall be the Green Building Standards Code of the Town. In accordance with California Health and Safety Code Section 17958.7, express findings that modifications to the Green Building Standards Code are reasonably necessary because of local climatic, geological, or topographical conditions are either already on file with the California Building Standards Commission or will be filed prior to the effective date of the ordinance codified in this section.

B. Subsection 102.3.1 of the California Green Building Standards Code is hereby added to read as follows:

102.3.1 Third party verification.

Third party verification of compliance for applicable building measures of this code is required and shall be provided by a Green Building Specialist as defined in chapter 2 of this code.

C. Section 202 of the California Green Building Standards Code is hereby amended to add the following definitions:

APPLIED WATER TURF CALCULATOR: An applied water turf calculator is a tool that uses data and methodology from the California Department of Water Resources to estimate the irrigation water requirements for turf minus any water supplied by effective rainfall and effective ground water seepage. The calculator uses the evapotranspiration of applied water (ETaw) for cool-season and warm-season turf that was calculated based on a six-year period of climate data specific to a 4 × 4 km grid spacing within the town.

GREEN BUILDING SPECIALIST: A green building specialist is a person that is LEED certified for the building type, trained through Build It Green as a certified green building professional, or similar qualifications as approved by the planning director or their designee.

RAINWATER CATCHMENT SYSTEM: Rainwater catchment system means the collected precipitation from rooftops and other above-ground impervious surfaces that is stored in catchment tanks for later use.

TURF: Turf means a ground cover surface of mowed grass. All of the following qualify as turf: annual bluegrass, Kentucky bluegrass, Perennial ryegrass, Red fescue, and tall fescue (cool-season grasses). Bermuda grass, Kikuyu grass, Seashore Paspalum, St. Agustine grass, Zoysia grass, and Buffalo (warm-season grasses).

D. Section 202 of the California Green Building Standards Code is hereby amended to incorporate the following amendment to the term below:

NEWLY CONSTRUCTED (or NEW CONSTRUCTION): A newly constructed building (or new construction) does not include additions, alterations or repairs. For the purposes of this code, additions, alterations and additions that include alterations to existing low-rise residential buildings for which building permit(s) have been issued within any 12-month period that collectively exceeds more than 50 percent of the existing floor area, 50 percent of the existing wall area or when the combination of the percentages of affected floor area and affected wall area exceeds 50 percent are treated as newly constructed (or new construction). In calculating these percentages, the following guidelines shall apply:

(1) Calculation of Percentage of Affected Floor Area (PFA): The floor area of any addition, all rooms affected by any addition, and the floor area of all rooms affected by structural changes made in the building, such as walls, columns, beams or girders, floor or ceiling joists and coverings, roof rafters, roof diaphragms, footings, piles or retaining walls or similar components, shall be included in computing the floor areas for applying this section.

(2) Calculation of Percentage of Affected Wall Area (PWA): The calculated wall area affected shall include all interior and exterior walls where no studs are proposed to be remain or if some studs remain and/or if the surface of both sides of the studs are proposed to be removed such that one can see through the wall.

(3) Calculation of Combination of Percentage of Affected Floor Area (PFA) and Wall Area (PWA): The combination of the percentage of affected floor as described above plus the percentage of wall area as described above (PFA + PWA > 50%).

E. Subsection 301.1.1 of the California Green Building Standards Code is hereby amended to read as follows:

301.1.1 Additions and alterations.

[HCD] the mandatory provisions of Chapter 4 shall be applied to additions and alterations of existing residential buildings where the addition or alteration increases the building's conditioned area, volume or size. The requirements shall apply only to and/or within the specific area of the addition or alterations.

The mandatory provisions of Section 4.106.4.2 may apply to additions or alterations of existing parking facilities or the addition of new parking facilities serving existing multi-family buildings. See Section 4.106.4.3 for application.

NOTE: Repairs including, but not limited to, resurfacing, restriping, and repairing or maintaining existing lighting fixtures are not considered alterations for the purposes of this section.

Exception:

All residential construction additions, alterations, repairs, and/or accessory dwelling unit conversions that include the replacement/upgrade to the main electric panel shall comply with Section 4.106.5.

F. Section 4.106.5 of the California Green Building Standards Code is hereby added to read as follows:

4.106.5 Residential additions, alterations and accessory dwelling unit conversions.

All residential construction additions, alterations, repairs, and/or accessory dwelling unit conversions that do not meet the definition of newly constructed that include the replacement/upgrade to the main electric panel shall comply with the following:

1. The replacement/upgrade to the main electric panel shall have:

a. The electrical capacity for and reservation of breaker space in the panel to accommodate the existing single-family electrical load and the future electrification of:

•

An electric stove and oven if the current stove and/or oven are gas;

•

An electric clothes dryer if the current clothes dryer is gas;

•

One level 2 electric vehicle charging equipment (EVCE);

•

Photovoltaic panels (PV); and

•

For a 240-volt circuit capable of providing electricity to operate a HPWH of comparable size to the existing gas fired water heater but a minimum of 30 amps per water heater.

b. All reserved breaker spaces shall be permanently marked as "For Future EVCE, PV and HPWH use."

G. Section 4.304.2 of the California Green Building Standards Code is hereby added to read as follows:

4.304.2 Reduction of potable water use on turf.

For all projects with landscapes that include the use of turf, install rainwater catchment system. Irrigation needs of turf should be calculated using the Applied Water for Turf Calculator. All rainwater catchment systems must be installed in compliance with California Plumbing Code in effect at the time of Building permit application.

1. Rainwater Catchment System Size. The rainwater catchment system size shall be determined by using the Applied Water for Turf Calculator. The rainwater catchment system will need to be sized in order to satisfy 50 percent of the estimated annual water demands for the first 500 square feet of turf installed on the project. The rainwater catchment system will need to be sized in order to satisfy 100 percent of the estimated annual water demands for installed turf that is greater than 500 square feet.

2. Alternative. A fully installed graywater system connected to an irrigation system that can satisfy all of the annual water demands of turf as identified in the Applied Water for Turf Calculator can be used as an alternative to installing a rainwater catchment system.

I. Section A4.204.1 of the California Green Building Standards Code is adopted as mandatory and amended to read as follows:

A4.204.1 Energy Efficiency. Alterations to existing residential buildings shall comply with Section A4.204.1.1.

A4.204.1.1 Altered Space-Conditioning System Serving Existing Single-Family Dwelling Units—Mechanical Cooling. When a space-conditioning system serving an existing single-family dwelling unit is altered in climate zones 1 through 14 and 16 by installation or replacement of an air conditioner, the altered system shall comply with either a, b, or c below in addition to the requirements for installation specified by Title 24, Part 6, Sections 150.2(b)1E and 150.2(b)1F:

a. A heat pump shall be the primary heating source and sized according to the system selection requirements specified by Title 24, Part 6 of Section 150.0(h)5. Supplemental heating may be provided by gas furnace or electric resistance heating as specified in Title 24, Part 6, Sections 150.0(h)7 and 150.0(i); or

b. An air conditioner shall meet all the requirements in either subsection I or II below:

I. Systems with Existing Duct Distribution Systems:

A. The duct system measured air leakage shall be equal to or less than 10 percent of the system air handler airflow as confirmed through field verification and diagnostic testing, per the requirements in Title 24, Part 6, Reference Residential Appendix Section RA3.1.4.3.1; and

Exception 1 to A4.204.1.1bIA: If it is not possible to meet the duct sealing requirements, all accessible leaks shall be sealed and verified through a visual inspection and a smoke test by a certified ECC-Rater utilizing the methods specified in Reference Residential Appendix Section RA3.1.4.3.5.

Exception 2 to A4.204.1.1bIA: Existing duct systems, constructed, insulated or sealed with asbestos.

B. Demonstrate, in every control mode, airflow greater than or equal to 300 CFM per ton of nominal cooling capacity through the return grilles, and an air-handling unit fan efficacy less than or equal to 0.45 W/CFM. The airflow rate and fan efficacy requirements in this section shall be confirmed through field verification and diagnostic testing, following the procedures outlined in Title 24, Part 6, Reference Residential Appendix RA3.3; and

Exception 1 to A4.204.1.1bIB: Systems unable to comply with the minimum airflow rate and system efficacy requirements shall demonstrate compliance by satisfying all of the following:

1. Following the procedures in Section RA3.3.3.1.5;

2. Installing a system thermostat that conforms to the specifications in Section 110.12;

3. For standard ducted systems (without zoning dampers), meet the applicable minimum total return filter grille nominal area requirements in Table 150.0-B or 150.0-C as confirmed by field verification and diagnostic testing in accordance with the procedures in Reference Residential Appendix Sections RA3.1.4.4 and RA3.1.4.5. The design clean-filter pressure drop requirements specified by Section 150.0(m)12D for the system air filter(s) shall conform to the requirements given in Tables 150.0-B and 150.0-C.

Exception 2 to Section A4.204.1.1bIB: Multispeed compressor systems or variable speed compressor systems shall verify air flow (cfm/ton) and fan efficacy (Watt/cfm) for system operation at the maximum compressor speed and the maximum air handler fan speed.

Exception 3 to Section A4.204.1.1bIB: Gas furnace air-handling units manufactured prior to July 3, 2019 shall comply with a fan efficacy value less than or equal to 0.58 W/cfm as confirmed by field verification and diagnostic testing in accordance with the procedures given in Reference Residential Appendix RA3.3.

C. In all climate zones, refrigerant charge verification requirements shall meet the requirements in Title 24, Part 6 Section 150.2(b)1Fiib, including the minimum airflow rate specified in Section 150.2(b)1Fiia; and

D. Vented attics shall have insulation installed to achieve a U-factor of 0.020 or insulation installed at the ceiling level shall result in an insulated thermal resistance of R-49 or greater for the insulation alone; luminaires not rated for insulation contact must be replaced or retrofitted with a fireproof cover that allows for insulation to be installed directly over the cover; and

Exception 1 to Section A4.204.1.1(b)ID: Dwelling units with at least R-38 existing insulation installed at the ceiling level.

Exception 2 to Section A4.204.1.1(b)ID: Dwelling units where the alteration would directly cause the disturbance of asbestos unless the alteration is made in conjunction with asbestos abatement.

Exception 3 to Section A4.204.1.1(b)ID: Dwelling units with knob and tube wiring located in the vented attic.

Exception 4 to Section A4.204.1.1(b)ID: Where the accessible space in the attic is not large enough to accommodate the required R-value, the entire accessible space shall be filled with insulation provided such installation does not violate Section 806.3 of Title 24, Part 2.5.

E. Air seal all accessible areas of the ceiling plane between the attic and the conditioned space including all joints, penetrations and other openings that are potential sources of air leakage by caulking, gasketing, weather-stripping or otherwise sealing to limit infiltration and exfiltration.

Exception 1 to Section A4.204.1.1bIE: Dwelling units with at least R-38 existing insulation installed at the ceiling level.

Exception 2 to Section A4.204.1.1 bIE: Dwelling units where the alteration would directly cause the disturbance of asbestos unless the alteration is made in conjunction with asbestos abatement.

Exception 3 to Section A4.204.1.1bIE: Dwelling units with atmospherically vented space heating or water heating combustion appliances located inside the pressure boundary of the dwelling unit.

II. Entirely New or Complete Replacement Duct Systems:

A. R-8 duct insulation shall be installed for all new ducts located in unconditioned space; and

B. The total duct system measured air leakage shall be equal to or less than 5 percent of the system air handler airflow as confirmed through field verification and diagnostic testing, per the requirements in Title 24, Part 6, Reference Residential Appendix Section RA3.1.4.3.1; and

C. Demonstrate, in every control mode, airflow greater than or equal to 350 CFM per ton of nominal cooling capacity through the return grilles, and an air-handling unit fan efficacy less than or equal to 0.35 W/CFM. The airflow rate and fan efficacy requirements in this section shall be confirmed through field verification and diagnostic testing, following the procedures outlined in Title 24, Part 6, Reference Residential Appendix RA3.3; and

D. In all climate zones, refrigerant charge verification requirements shall meet the requirements in Title 24, Part 6 Section 150.2(b)1Fiib; and

E. In Climate Zones 1-4, 6, and 8-16 if the air handler and ducts are located within a vented attic, vented attics shall have insulation installed to achieve a U-factor of 0.020 or insulation installed at the ceiling level shall result in an insulated thermal resistance of R-49 or greater for the insulation alone; luminaires not rated for insulation contact must be replaced or retrofitted with a fireproof cover that allows for insulation to be installed directly over the cover; and

Exception 1 to Section A4.204.1.1bIIE: In Climate Zones 1, 3, and 6, dwelling units with at least R-19 existing insulation installed at the ceiling level.

Exception 2 to Section A4.204.1.1bIIE: Dwelling units where the alteration would directly cause the disturbance of asbestos unless the alteration is made in conjunction with asbestos abatement.

Exception 3 to Section A4.204.1.1bIIE: Dwelling units with knob and tube wiring located in the vented attic.

Exception 4 to Section A4.204.1.1bIIE: Where the accessible space in the attic is not large enough to accommodate the required R-value, the entire accessible space shall be filled with insulation provided such installation does not violate Section 806.3 of Title 24, Part 2.5.

F. In Climate Zones 2, 4, and 8-16, air seal all accessible areas of the ceiling plane between the attic and the conditioned space including all joints, penetrations and other openings that are potential sources of air leakage by caulking, gasketing, weather-stripping or otherwise sealing to limit infiltration and exfiltration.

Exception 1 to Section A4.204.1.1bIIF: Dwelling units with at least R-19 existing insulation installed at the ceiling level.

Exception 2 to Section A4.204.1.1bIIF: Dwelling units where the alteration would directly cause the disturbance of asbestos unless the alteration is made in conjunction with asbestos abatement.

Exception 3 to Section A4.204.1.1bIIF: Dwelling units with atmospherically vented space heating or water heating combustion appliances located inside the pressure boundary of the dwelling unit.

c. Performance approach.

The energy budget for alterations is expressed in terms of Long-term System Cost (LSC), and the altered component(s) and any newly installed equipment serving the alteration shall meet the applicable requirements of Subsections A, B, and C below.

A. The altered components shall meet the applicable requirements of Title 24, Part 6, Sections 110.0 through 110.9, Sections 150.0(a) through (l), Sections 150.0(m)1 through 150.0(m)10, and Sections 150.0(p) through (q). Entirely new or complete replacement mechanical ventilation systems as these terms are used in Section 150.2(b)1L, shall comply with the requirements in Section 150.2(b)1L. Altered mechanical ventilation systems shall comply with the requirements of Section 150.2(b)1M. Entirely new or complete replacement space-conditioning systems, and entirely new or complete replacement duct systems, as these terms are used in Sections 150.2(b)1C and 150.2(b)1Diia, shall comply with the requirements of Sections 150.0(m)12 and 150.0(m)13.

B. The standard design for an altered component shall be the higher efficiency of existing conditions or the requirements stated in Table A4.204.1.1-A. For components not being altered, the standard design shall be based on the existing conditions. When the third party verification option is specified as a requirement, all components proposed for alteration for which the additional credit is taken, must be verified by a certified ECC-rater.

Table A4.204.1.1-A Standard Design for an Altered Component

C. The proposed design shall be based on the actual values of the altered components.

Exception 1 to Section A4.204.1.1: Where the capacity of the existing main electrical service panel is insufficient to supply the electrical capacity of a heat pump and where the existing main electrical service panel is sufficient to supply a new or replacement air conditioner, as calculated according to the requirements of California Electrical Code Article 220.83 or Article 220.87. Documentation of electrical load calculations in accordance with Article 220 must be submitted to the enforcement agency prior to permitting for both the heat pump and proposed air conditioner.

Exception 2 to Section A4.204.1.1: Where the required capacity of a heat pump to meet the system selection requirements of Section 150.0(h)5 is greater than or equal to 12,000 Btu/h more than the greater of the required capacity of an air conditioner to meet the design cooling load OR the capacity of the existing air conditioner. Documentation of heating and cooling load calculations in accordance with 150.0(h) must be submitted to the enforcement agency prior to permitting for both the heat pump and proposed air conditioner.

J. Section 101.12 of the California Green Building Standards Code is hereby added to read as follows:

101.12 Hardship or infeasibility exemption.

If an applicant for a covered project believes that circumstances exist that make it a hardship or infeasible to meet the requirements of Subsections 4.106.5 or A4.204.1, the applicant may request an exemption as set forth below. In applying for an exemption, the burden is on the applicant to show hardship or infeasibility.

1. Application. Any request for an exemption must be included at the time of application submittal. The applicant shall indicate the maximum threshold of compliance he or she believes is feasible for the covered project and the circumstances that he or she believes create a hardship or make it infeasible to fully comply with this chapter. Circumstances that constitute hardship or infeasibility include, but are not limited to, the following:

a. There is conflict with the compatibility of the above referenced sections with other town goals, such as those requiring historic preservation;

b. There is conflict with the compatibility of the above referenced sections and the California Building Standards Code;

c. There is conflict with the compatibility of the above referenced sections and the town's zoning ordinance and/or architectural review criteria; and/or

d. There is a lack of commercially available technologies to comply with the above referenced sections.

2. Review by Architectural and Site Control Commission. For any covered project for which an exemption is requested and architectural and site control review is required, the architectural and site control commission shall provide a recommendation to the planning director or their designee regarding whether the exemption shall be granted, conditionally granted or denied, along with its recommendation on the project. For any project for which an exemption is requested based on the historic character of the building or site, the town historian shall provide a recommendation to the planning director or their designee regarding whether the exemption shall be granted or denied and shall determine whether the project is consistent with the Secretary of the Interior's Standards for Historic Rehabilitation.

3. Decision by Planning Director (or their designee). The planning director or their designee shall make a determination based on the information provided. The planning director or his/her designee shall determine the maximum feasible threshold of compliance reasonably achievable for the project. The decision of the planning director or their designee shall be provided to the applicant in writing.

a. If the planning director or their designee determines that it is a hardship or is infeasible for the applicant to meet the requirements of this chapter, the request shall be granted. Notwithstanding, the applicant shall be required to comply with this chapter in all other respects and shall be required to achieve, in accordance with this chapter, the threshold of compliance determined to be reasonably achievable by planning director or their designee.

b. If the planning director or their designee determines that it is reasonably possible for the applicant to fully meet the requirements of this chapter, the request shall be denied. The project and compliance documentation shall be modified to comply with this chapter prior to further review of any pending planning or building application.

c. The planning director or their designee's decision shall be final.

(Ord. 2025-454, § 13, 2026)

A. The 2025 Wildland-Urban Interface Code, Title 24, Part 7, referred to throughout this Chapter as the "Wildland-Urban Interface Code," is hereby adopted and, except as to additions, deletions and amendments hereinafter described, made a part hereof, the same as if fully set forth in this section, and shall be the Wildland-Urban Interface Code of the Town. In accordance with California Health and Safety Code Section 17958.7, express findings that modifications to the Wildland-Urban Interface Code are reasonably necessary because of local climatic, geological, or topographical conditions are either already on file with the California Building Standards Commission or will be filed prior to the effective date of the ordinance codified in this section.

B. Section 202 of the California Wildland-Urban Interface Code is hereby amended to read as follows:

NEW BUILDING. For the purposes of this chapter, alterations, additions and additions that include alterations to existing buildings for which building permit(s) have been issued within any 12-month period that collectively exceeds more than 50 percent of the existing floor area, 50 percent of the existing wall area or when the combination of the percentages of affected floor area and affected wall area exceeds 50 percent are treated as new buildings. In calculating these percentages, the following guidelines shall apply:

a. Calculation of Percentage of Affected Floor Area (PFA): The floor area of any addition, all rooms affected by any addition, and the floor area of all rooms affected by structural changes made in the building, such as walls, columns, beams or girders, floor or ceiling joists and coverings, roof rafters, roof diaphragms, footings, piles or retaining walls or similar components, shall be included in computing the floor areas for applying this section.

b. Calculation of Percentage of Affected Wall Area (PWA): The calculated wall area affected shall include all interior and exterior walls where no studs are proposed to be remain or if some studs remain and/or if the surface of both sides of the studs are proposed to be removed such that one can see through the wall.

c. Calculation of Combination of Percentage of Affected Floor Area (PFA) and Wall Area (PWA): The combination of the percentage of affected floor as described above plus the percentage of wall area as described above (PFA + PWA > 50%).

C. Subsection 504.2 of the California Wildland-Urban Interface Code is hereby amended to add the following two exceptions:

504.2 Roof Coverings.

Exceptions:

5. Roof covering replacement that affects 25% or less of the building structure.

6. Cap Sheet is not required when no less than 1 inch of mineral wool or other noncombustible material is located between the roofing material and wood framing or deck.

Alternately, a Class A fire rated roof underlayment, tested in accordance with ASTM E108, shall be permitted to be used. If the sheathing consists of exterior fire-retardant-treated wood, the underlayment shall not be required to comply with a Class A classification. Bird stops shall be used ate the eaves when the profile fits, to prevent debris at the eave. Hip and ridge caps shall be mudded in to prevent intrusion of fire or embers.

D. Subsection 504.5.2 of the California Wildland-Urban Interface Code is hereby amended to add the following two exceptions:

504.5.2 Exterior wall coverings.

Exception:

5. Alterations to existing exterior wall coverings that affect less than 10% of the exterior of the building.

6. Exterior columns supporting roof structures and trellises wrapped with noncombustible material. Ignition resistant or combustible veneers over noncombustible material is prohibited.

E. Subsection 507.1 of the California Wildland-Urban Interface Code is hereby amended to read as follows:

507.1 General.

The roof covering on buildings or structures in existence prior to the adoption of this code that are replaced or have 25 percent or more replaced in a 12-month period shall be replaced with a roof covering required for new construction in accordance with Sections 504.2 and 504.2.1. All portions of a roof covering applied during an addition, alteration or repair to an existing structure shall meet at least a Class A fire classification.

(Ord. 2025-454, § 14, 2026)

The 2025 California Referenced Standards Code, Title 24, Part 12, referred to throughout this Chapter as the "Referenced Standards Code," is hereby adopted and made a part hereof, the same as if fully set forth in this section, and shall be the Referenced Standards Code of the Town.

(Ord. 2025-454, § 15, 2026)

The 2025 California Administrative Code, Title 24, Part 1, referred to throughout this Chapter as the "Administrative Code," is hereby adopted and made a part hereof, the same as if fully set forth in this section, and shall be the Administrative Code of the Town.

(Ord. 2025-454, § 16, 2026)