HEAT PUMP INSTALLATION IN MISSION VIEJO, CA

Because the city routes every permit through one online system, the practical step is to describe the whole job when the application is opened: new outdoor and indoor equipment, any ductwork changes, and any new circuit or panel work. That way the city can tell us how the pieces are classified before work starts.

• City of Mission Viejo: Building Services (opens in a new tab)
• City of Mission Viejo: Client Self Service (opens in a new tab)
• City of Mission Viejo: Work Exempt from Building Permits (opens in a new tab)
• City of Mission Viejo: Residential Electrical Requirements (opens in a new tab)
• City of Mission Viejo: Building Inspection Request (opens in a new tab)

Mission Viejo is inland from the beach cities. NOAA explains that the marine layer forms when cold ocean water cools the air above it, and that how far inland it reaches depends on the weather. The National Weather Service in San Diego says the weather can be very different between beaches and inland areas.

That is why we size a heat pump from the house instead of the city. Windows, sun exposure, insulation and ductwork decide how hard the system works on a warm afternoon and on a cool night, and the assessment looks at each of them.

• NOAA JetStream: The Marine Layer (opens in a new tab)
• National Weather Service San Diego: The Weather Guide, 6th Edition, 2012 (PDF) (opens in a new tab)

Wherever you live, the same state rules shape a heat pump changeout. CSLB's HVAC checklist tells homeowners to make sure the contractor obtains a building permit and that the building department performs all required inspections. The California Energy Commission's 2025 Energy Code, which applies to buildings whose permit applications are applied for on or after January 1, 2026, adds testing to the permit.

• Duct sealing and verification: the Energy Commission says replacing the outdoor unit or the indoor unit of a split system, by itself, triggers duct sealing and field verification. An independent rater, called an ECC-Rater, verifies the result.
• Refrigerant charge: the Commission's compliance manual calls for refrigerant charge verification on heat pumps in all climate zones. For air conditioners it applies in climate zones 2 and 8 through 15.

Which tests apply depends on the equipment and your address. We do not assign climate zones to cities, so ask your contractor or building department which zone your address is in and which of these tests apply.

• CSLB: HVAC Installation Fact Sheets and HVAC Checklist for consumers (PDF) (opens in a new tab)
• California Energy Commission: 2025 Building Energy Efficiency Standards (opens in a new tab)
• California Energy Commission: 2025 Single-Family Heating, Ventilation, and Air Conditioning (HVAC) (opens in a new tab)
• California Energy Commission: 2025 Single-Family Residential Compliance Manual, Chapter 9 (alterations and repairs to existing homes) (opens in a new tab)

If your home is in a homeowners association that requires approval for physical changes, Civil Code Section 4765 sets the ground rules for that review: the association's decision is to be in writing, and a disapproval has to explain why and describe how to ask for reconsideration. HOA approval and a city permit are separate. One does not replace the other.

An association may ask about anything that shows from outside, such as where the outdoor unit sits and how refrigerant lines run along the wall. Ask for its rules before the schedule is set, and give the association and the city the same drawings.