Palo Alto, California building code

Palo Alto enforces 2025 CBC, T24 Pt 2 based on 2024 IBC with 2 local amendments on top (Ord. 5674). The amendments are the part that gets sets corrected. The state edition is only the floor. Palo Alto sits in Santa Clara County.

Current edition
2025 Title 24
Prior edition
2022 Title 24

Edition changeover: Projects with a complete application on or before 2025-12-31 may still be reviewed under the 2022 Title 24.

Adopted code and local amendments by discipline

Adopted code editions and local amendments by discipline
DisciplineAdopted codeLocal amendment
Building2025 CBC, T24 Pt 2 based on 2024 IBCPalo Alto 2025 Building Code, Ord. 5674 (adopted 2025-10-20, eff. 2025-11-20; PAMC Title 16 Ch. 16.04; companions 5675-5679, 5682)Stricter of state or local governs
Residential2025 CRC, T24 Pt 2.5 based on 2024 IRCn/a
Existing buildings2025 CEBC, T24 Pt 10 based on 2024 IEBCn/a
Fire2025 CFC, T24 Pt 9 based on 2024 IFCn/a
Electrical2025 CEC, T24 Pt 3 based on 2023 NECn/a
Mechanical2025 CMC, T24 Pt 4 based on 2024 UMCn/a
Plumbing2025 CPC, T24 Pt 5 based on 2024 UPCn/a
Energy2025 Energy Code, T24 Pt 6n/a
Green / sustainability2025 CALGreen, T24 Pt 11n/a
Accessibility2025 CBC Ch 11A/11B, T24 Pt 2n/a
Wildland-urban interface2025 CA-WUIC, T24 Pt 7 based on 2024 IWUICn/a
Historical buildings2025 CHBC, T24 Pt 8n/a
Administrative2025 CAC, T24 Pt 1n/a
ZoningNo state-adopted codeLocal zoning ordinance (city or county), subject to state preemptionLocal text supersedes the state code

What Palo Alto actually amended

Quoted from the adopted ordinance. These are the provisions that differ from the state code, which is where most correction lists come from. Excerpts, not the whole ordinance. Follow the source link for the full text.

16.19.090 · 16.19.090

Section 324 Dwelling unit and congregate residence superficial floor area. Section 324 of Chapter 3 of the California Existing Building Code is added to read: 324 Dwelling unit and congregate residence superficial floor area. Every dwelling unit and congregate residence shall have at least one room which shall have not less than 120 square feet of superficial floor area. Every room which is used for both cooking and living or both living and sleeping purposes shall have not less than 144 square feet of superficial floor area. Every room used for sleeping purposes shall have not less than 70 square feet of superficial floor area. […]

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: Building: 1. One-story detached accessory structures used as tool and storage sheds, playhouses and similar uses, provided that the floor area does not exceed 120 square feet (11.15 m2). It is permissible that these structures still be regulated by Section 710A, despite exemption from permit. 2. […]

113.1

Appeals. A person requesting an order, decision, or determination made by the building official relative to the California Building Code (as amended) may appeal such order, decision or determination by completing a request for hearing form and returning it to the City within thirty calendar days from the date of the decision, together with all applicable fees authorized by the City’s Municipal Fee Schedule. […]

113.3 · Hearing procedures

(a) No appeal hearing before a hearing officer shall be noticed unless the applicable fee(s) been paid in advance in accordance with Section 113.1. (b) A hearing before the hearing officer shall be set for a date that is not less than fifteen days and not more than sixty days from the date that the request for hearing is filed in accordance with the provisions of this chapter. […]

405.2.3.1.2 · 405.2.3.1.2

Reduced CEBC level seismic forces  G 45 0290186_20250923_ms29 Docusign Envelope ID: 115F413D-23A8-4D39-9815-3A915CB8F3F2 Appx. A1 Appx. A2 Appx. A3 Appx. A4 Seismic Strengthening Provisions for Unreinforced Masonry Bearing Wall Buildings Earthquake Hazard Reduction in Existing Reinforced Concrete and Reinforced Masonry Wall Buildings with Flexible Diaphragms Prescriptive Provisions for Seismic Strengthening of Cripple Walls and Sill Plate Anchorage of Light, Wood- Frame Residential Buildings Earthquake Risk Reduction in Wood- Frame Residential Buildings with Soft, Weak or Open Front Walls     G, T G, T G, T G, T Appx. […]

903.2

Automatic sprinkler systems, where required. Approved automatic sprinkler systems in new buildings and structures and in existing modified buildings and structures, shall be provided in the locations described in this section. Automatic fire sprinklers shall be installed per the requirements set forth in Sections 903.2.1 through 903.2.18 and as follows, whichever is the more restrictive: 1. An automatic sprinkler system shall be provided throughout all new buildings and structures. Exception: New non-residential occupancies, buildings or structures that do not exceed 350 square feet of building area and contain no plumbing fixtures. 2. […]

903.3.1.1

NFPA 13 sprinkler systems. Where the provisions of this code require that a building or portion thereof be equipped throughout with an automatic sprinkler system in accordance with this section, sprinklers shall be installed throughout in accordance with NFPA 13 and State and local requirements except as provided in Section 903.3.1.1. 1. For new buildings having no designated use or tenant, the minimum sprinkler design density shall be Ordinary Hazard Group II/1500 square feet. 2. Where future use or tenant is determined to require a higher density, the sprinkler system shall be augmented to meet the higher density. 3. […]

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 or to an egress balcony that leads to a public way. Exceptions: 1. […]

1809.7

Prescriptive footings for light-frame construction. Where a specific design is not provided, concrete or masonry-unit footings supporting walls of light-frame construction shall be permitted to be designed in accordance with Table 1809.7. TABLE 1809.7 abcd Prescriptive Footings Supporting Walls of Light-Frame Construction Number of Floors Supported by the Footing e 1 & 2 3 Group U Occupancies Thickness of Foundation Wall (inches) 8 8 8 Width of Footing (inches) 15 18 12 Thickness of Footing (inches) 8 8 8 Depth of Foundation Below Natural Surface of Ground or Finish Grade (inches) 20 30 12 ADU Conversionsf 8 12 8 12 a. […]

3304.1 · 3304.1

Excavation and fill    G, T Appx. I Patio Covers    A, G Appx. J Grading (Section J109.4 Drainage across property lines)    G, T Appx. P Emergency Housing    A, C, G, T 44 0290186_20250923_ms29 Docusign Envelope ID: 115F413D-23A8-4D39-9815-3A915CB8F3F2 Exhibit B FINDINGS FOR LOCAL AMENDMENTS TO CALIORNIA EXISTING BUILDING CODE, Title 24, Part 10 Section 17958 of the California Health and Safety Code provides that the City may make changes to the provisions of the California Building Standards Code. […]

Source: www.paloalto.gov

Overlays that can apply

Mapped hazard and district overlays stack on top of the adopted code. These are the overlays recorded for Santa Clara County. They apply by parcel, not jurisdiction-wide, so confirm the parcel before assuming one is in play. Check CAL FIRE's fire hazard severity viewer and FEMA's flood map service.

  • Very High Fire Hazard Severity Zone
  • FEMA mapped flood hazard area

State law that overrides local zoning here

When one of these applies, the state statute governs over a conflicting local standard. This is the most common reason a local rule someone quotes you turns out not to be enforceable against a project.

  • Gov. Code 66310 et seq.

    State ADU law preempts local zoning that would preclude a conforming ADU/JADU.

    Applies when: project includes an ADU or JADU

  • Gov. Code 65915

    State Density Bonus Law concessions/waivers override local development standards.

    Applies when: project requests a density bonus

  • Gov. Code 65852.21 / 66411.7

    SB 9 urban lot split / two-unit ministerial approval preempts conflicting local standards.

    Applies when: project is an SB 9 lot split or two-unit development

Sources

Common questions

What building code does Palo Alto use?

Palo Alto enforces 2025 CBC, T24 Pt 2 based on 2024 IBC, the edition adopted statewide in California, amended locally in 2 disciplines (Ord. 5674).

Does Palo Alto amend the California code?

Yes: building, zoning. For building, the rule is: stricter of state or local governs.

Where do I confirm the code edition for a Palo Alto permit?

With the city building department that will review the permit. Adoption ordinances are amended on a local schedule, and a set submitted days apart can fall under different editions during a changeover.

Nearby jurisdictions in Santa Clara County

Statewide

Check a plan set against Palo Alto code

Knowing the adopted edition is the easy half. Architechtura reads your drawings, resolves which of these provisions actually apply to the project, and returns the corrections a plan checker would write up, each one cited to the section it came from.

Your first check is free, no card required.

Compiled from published state and municipal adoption ordinances. Local governments amend their codes on their own schedule, and a pending ordinance can change what applies to your permit. Confirm the governing edition with the building department before you submit. This page is reference information, not a code determination.