AC changeout permits in Sunnyvale, CA
General California guidance last updated May 22, 2026 · Sunnyvale data verified August 10, 2026
What HVAC contractors need to know about pulling a ac changeout permit in Sunnyvale (Santa Clara County).
Short answer
In California, replacing a central AC condenser, coil, or furnace needs a mechanical permit (and often electrical for the condenser circuit), pulled by a licensed C-20 contractor. The work is governed by the California Mechanical Code (Title 24, Part 4) and the California Energy Code (Title 24, Part 6), and most residential replacements require third-party HERS testing for duct leakage and refrigerant-charge verification.
Sunnyvale accepts submittal through the E-OneStop Online Services (Tyler EnerGov) and has adopted the 2025 California Building Standards Code (with Sunnyvale amendments). Fee details and sources are below.
Sunnyvale permit data
Sourced from public City of Sunnyvale documents — every field carries the source URL and verification date.
- Permit portal
- E-OneStop Online Services (Tyler EnerGov)
verified Aug 10, 2026 · source · All services are online through E-OneStop — apply for permits, search permit and plan history, upload documents, receive and respond to city comments, schedule inspections, and make payments
- Adopted code edition
2025 California Building Standards Code (with Sunnyvale amendments)
verified Aug 10, 2026 · source · The city lists the 2025 California Building, Residential, Electrical, and companion codes as current; adopted by Ordinance 3248-25 on October 21, 2025 (Sunnyvale Municipal Code Ch. 16.16: https://ecode360.com/42720766), with local amendments effective January 1, 2026 per the council ordinance record (https://sunnyvaleca.legistar.com/LegislationDetail.aspx?ID=7682689&GUID=33162351-432E-4616-996F-0D05C49AF7D2)
- Fee schedule
- FY 2025-26 Building Permit Fees — effective August 18, 2025
verified Aug 10, 2026 · source · A FY 2026-27 Land Development fee schedule is already posted on the same page — watch for a FY 2026-27 building-fee update
The general picture in California
An HVAC changeout is permitted mechanical work in nearly every California jurisdiction. California's Title 24 Part 6 energy standards require third-party HERS verification on most residential AC and furnace replacements — typically duct-leakage testing, refrigerant-charge verification, and airflow when ducts are altered. Replacements may also require updating combustion air, condensate drainage, condenser disconnects and clearances, and a smart thermostat under some prescriptive packages. Heat-pump replacements add electrical-load and circuit considerations.
For deeper background that isn't Sunnyvale-specific, see the statewide ac changeout guide.
Typically needs a permit
AC changeout itself triggers a permit in nearly every California jurisdiction, Sunnyvale included. Sunnyvale-specific variations are confirmed with the issuing department above.
Usually doesn't (general norm)
- Replacing a thermostat with a like-for-like (non-smart) unit
- Replacing a capacitor, contactor, or fan motor on the existing condenser (repair, not replacement)
- Cleaning coils, replacing filters, or relighting the pilot
Documents & plans generally required
- Mechanical permit application (and electrical permit when the condenser circuit is replaced or upsized)
- Contractor license and city business registration
- Cut sheets for the new equipment (condenser, coil, furnace/air handler) with AHRI match
- Title 24 Part 6 compliance documentation (CF1R, plus CF2R/CF3R from the HERS rater)
- Refrigerant type and line-set details (especially R-410A → R-454B / A2L transitions)
- Condensate drainage route and termination
- Electrical disconnect and condenser-circuit details if changed
Common reasons ac changeout applications get bounced
Code-rooted patterns across California — not a Sunnyvale-specific rejection rate.
- Missing Title 24 Part 6 documentation or HERS registration
- AHRI match certificate missing or doesn't match the proposed condenser + coil combination
- Refrigerant type / line-set compatibility not addressed (A2L compliance for new installs)
- Condenser placement clearances not shown (NEC 110.26 + manufacturer's clearance + setback ordinances)
- Condensate drainage to an unapproved location or without a secondary safety drain/switch
- No detail on duct-leakage testing or refrigerant-charge verification on a duct-altered system
The inspection sequence
A typical order — the number of stops and exact sequence vary by jurisdiction and scope.
- 1Rough/in-progress not typically required for like-for-like equipment swaps
- 2HERS verification (third-party rater) for duct leakage and refrigerant charge as applicable
- 3Final inspection with the equipment installed, energized, and tested; HERS certificates filed
Licensing — who can pull it
HVAC changeouts in California are generally performed by a C-20 (Warm-Air Heating, Ventilating and Air-Conditioning) licensed contractor; a B (General Building) contractor may pull within a larger project under CSLB rules. The licensed contractor doing the work typically pulls the permit.
Other verified Sunnyvale notes
One-Stop Permit Center: City Hall, 456 W. Olive Ave., 2nd floor; 408-730-7444; Planning, Engineering, and Building counters open weekdays 8 AM–noon and 1–5 PM (closed weekends and City holidays).
verified Aug 10, 2026 · source
Over-the-counter (OTC) building plan-check appointments run in the mornings — generate the building permit online first with the project description "OTC", submit plans, then request the in-person slot.
verified Aug 10, 2026 · source
Building inspections are scheduled through the online service or by phone at 408-730-7790; the general contractor is responsible for scheduling and being present for all inspections.
verified Aug 10, 2026 · source
Frequently asked questions
Do I need a permit for a like-for-like AC changeout in California?
Generally yes. Even a like-for-like AC condenser or furnace replacement triggers a mechanical permit and Title 24 Part 6 compliance (HERS testing for duct leakage and refrigerant charge) in nearly every California city. Repairs to existing equipment generally don't.
What is HERS verification and why is it required?
Title 24 Part 6 requires third-party HERS (Home Energy Rating System) raters to verify specific measures on residential replacements — most commonly duct leakage and refrigerant charge. The rater's CF2R/CF3R certificates are filed with the permit; missing HERS documentation is a top reason for rejection or failed final.
Do I need an electrical permit too?
If the condenser circuit, disconnect, or breaker is replaced or upsized, yes — that's electrical work. Most jurisdictions bundle it under the mechanical permit but require electrical scope on the application. Heat-pump conversions almost always need an electrical permit.
How does the A2L refrigerant transition affect permits?
New systems shipped after the EPA's 2025 A2L transition use mildly-flammable refrigerants (R-454B, R-32) requiring listed line sets, leak-detection where applicable, and updated installation practices. The application and cut sheets should reflect the refrigerant type; some jurisdictions are still updating their checklists.
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