Do I Need a Permit to Install an Air Conditioner?

Short answer: in most California jurisdictions, yes—installing or replacing central AC, a heat pump, or a mini‑split typically requires a permit. Permits exist to verify safety, energy efficiency, noise compliance, and proper refrigerant and electrical work. While each city’s rules vary, Los Angeles County and nearby areas almost always require a mechanical permit for AC installs, and many jobs also trigger electrical permits and energy compliance testing.

Why permits matter for AC installations

Permits protect homeowners, occupants, and neighbors. They ensure proper equipment sizing, safe electrical and refrigerant connections, correct seismic anchorage, fire-safe roof penetrations, and code-compliant ductwork and ventilation. They also document compliance with California Title 24 energy standards and local noise ordinances—issues that can be costly to fix after the fact.

When a permit is required

• Installing new central AC or heat pump systems
• Replacing a condenser, air handler, furnace-coil combination, or packaged unit
• Installing or adding indoor heads for ductless mini-splits
• Running new circuits, upgrading breakers, or adding a disconnect
• Adding or replacing ducts, plenums, or significant ventilation changes
• Roof-mounted units, new curbs, structural changes, or crane lifts
• Any work requiring Title 24/HERS compliance or new refrigerant lines

Note: What seems like a “simple swap” often still requires a permit because inspectors must verify electrical sizing, clearances, seismic strapping, refrigerant line sizing, and energy code paperwork.

What usually doesn’t require a permit

• Routine maintenance: filter changes, cleaning coils, replacing batteries
• Like-for-like minor parts: certain sensors, some low-voltage components
• Portable or window AC units that plug into a standard receptacle (subject to HOA, noise, or window safety rules)

Always confirm with your local building department; thresholds vary by city.

Who issues the permit in our region

Authority depends on where the property sits. In the City of Los Angeles, permits are typically issued by LADBS. In unincorporated areas of Los Angeles County, the County’s building department applies. Incorporated cities throughout Los Angeles County—and in adjacent Orange County, Ventura County, and Western Riverside County—have their own building and safety offices (for example: Santa Monica, Pasadena, Glendale, Burbank, Long Beach, Anaheim, Irvine, Santa Ana, Huntington Beach, Thousand Oaks, Oxnard, Riverside, Corona, Temecula, Moreno Valley). Requirements are similar but not identical.

What the permit process looks like

1. Pre-design: Load calculations and equipment selection. Proper sizing (Manual J/S/D methods or equivalent) and AHRI-matched equipment help satisfy Title 24.
2. Application: Mechanical (and sometimes electrical/structural) permits are filed. Some replacements are over-the-counter; others require plan check.
3. Energy compliance: Title 24 forms are completed, and HERS testing may be required (duct leakage, airflow, refrigerant charge verification, fan watt draw, smart thermostat, etc.).
4. Installation: Work follows manufacturer instructions and local code: clearances, anchorage, line set sizing, traps, insulation, condensate routing, disconnects, GFCI where required, and proper sealing.
5. Inspections: Rough and/or final inspections verify code compliance. HERS rater tests are submitted to finalize documentation.

How long does it take and what does it cost?

Simple residential change-outs can be permitted within a day to a week, depending on jurisdiction and workload. Plan-checked projects (multi-family, commercial, roof structural work) take longer. Permit fees vary widely but often range a few hundred dollars for straightforward residential replacements, with additional costs for plan check, HERS testing, and any structural or electrical upgrades.

Consequences of skipping the permit

• Stop-work orders, fines, and mandated rework
• Problems during sale, appraisal, or refinancing if unpermitted work is flagged
• Manufacturer warranty or utility rebate complications
• Insurance issues: Many insurers expect permitted, code-compliant installations; claims related to unpermitted HVAC work can be disputed or denied
• Safety and performance risks: Undersized wiring, improper breakers, poor refrigerant charge, or inadequate duct sealing can cause fires, premature failures, or unhealthy indoor air

DIY considerations and safety

Air conditioning work involves high-voltage power, pressurized refrigerants, combustion air pathways (in combined systems), and penetrations through roofs and walls. Refrigerant handling requires EPA Section 608 certification, and electrical changes must meet code. Improper work can be dangerous, void warranties, and jeopardize insurance coverage. In many cases, local and state rules allow only licensed contractors to pull permits for HVAC work unless the property owner takes full “owner-builder” responsibility—and even then, inspections and compliance are required.

Documentation you may need

• Site plan or equipment location diagram with setbacks and clearances
• Manufacturer data sheets, AHRI reference numbers, and noise ratings
• Electrical one-line or load calculations when new circuits are added
• Title 24 energy compliance forms and planned HERS tests
• Structural details for roof curbs or platforms and seismic anchorage details
• Crane/lift plan if required, plus traffic control permits where applicable
• HOA approvals, if any

Local nuances across our service area

Across Los Angeles County and nearby counties (Orange, Ventura, Western Riverside), most jurisdictions require permits for new or replacement AC and heat pumps. Some cities offer express permits for one-for-one swaps; others require plan review for duct changes, added tonnage, or roof equipment. Noise limits at the property line can affect outdoor unit placement, and coastal zones may require additional corrosion-resistant measures.

Commercial vs. residential projects

Residential projects generally move faster but still require Title 24 and, often, HERS. Commercial jobs commonly need stamped plans, mechanical and electrical design documents, and potentially air-balance reports. Roof access, structural calculations, and curb details are frequent triggers for plan check. Complex phasing to avoid downtime is another consideration for businesses.

About #1 AC Guys

#1 AC Guys is a family-run HVAC company based in Southern California with service across Los Angeles County and nearby areas including Orange County, Ventura County, and Western Riverside County. Our family of engineers spans four generations with 80+ years of engineering experience. Our mission is healthy air at home for a healthy life, and we specialize in both residential and commercial projects, especially large and complex builds. Our engineers have trained at manufacturer facilities for Fujitsu (Japan), Mitsubishi Elektrik (Thailand), Midea (China), Gree (China), and Hier (China).

Quick answers to common questions

• Do mini-splits need a permit? Yes, new installs and added heads typically do.
• Does a condenser-only swap need a permit? Usually yes, because electrical sizing, refrigerant, and Title 24 may apply.
• Do I need HERS testing? Often yes for residential change-outs under Title 24.
• Do window or portable ACs need permits? Generally no if they plug in, but HOA and safety rules still apply.
• Who pulls the permit? Typically a licensed contractor; owner-builders can apply in some jurisdictions but assume full responsibility.

Bottom line

In and around Los Angeles County, a permit is usually required to install or replace AC or heat pumps. Permits help ensure safety, code compliance, energy performance, and documentation for insurance and future property transactions. Because requirements vary by city, start with your local building department’s guidance and plan for Title 24/HERS where applicable. Proper design, documentation, and inspections keep your system safe, efficient, and compliant for years to come.