Roof, Plumbing, Electrical and HVAC in Older San Diego Rentals

Reviewed by Brendan McKee, Managing Broker, DRE #01882732, on October 20, 2026.

Each major system in a rental backs a habitability duty under California Civil Code § 1941.1: a waterproof roof and exterior, working plumbing and gas, hot and cold running water connected to sewage disposal, heating, and electrical lighting. Replacing one of these systems usually counts as an "alteration" under the 2025 California Energy Code, and the rules differ across San Diego County's four climate zones (7, 10, 14 and 15). Permits are local: in the City of San Diego, water heater, HVAC, panel and repipe jobs need a permit, while most re-roofs that leave the roof structure alone do not.

The short version

• The § 1941.1 list ties the roof, plumbing, hot water, heat and wiring to the owner's habitability duty.
• Under the 2025 Energy Code, replacing a system the code regulates is an alteration, not a repair, and brings code requirements with it.
• Climate zone matters: coastal CZ 7 is exempt from some rules that apply inland in CZ 10, 14 and 15. Confirm your address with the CEC climate zone tool.
• City of San Diego and unincorporated County permit rules differ; other cities set their own.
• In the City of San Diego, the whole sewer lateral, out to the main under the street, belongs to the property owner.
• California code does not require replacing an electrical panel just because it is old.

Systems at a glance

In the City, Simple (no-plan) permits are for houses and duplexes outside historic districts; apartments of three or more units, and historic properties, need plans. Water heaters have their own guide: water heaters in California rentals.

Roof

For single-family homes, duplexes and townhouses, the 2025 Energy Code applies cool roof rules when more than 50 percent of the roof is being replaced, including a new layer over the old one (Section 150.2(b)1I). Buildings of three or more units follow the multifamily section (180.2(b)1A), which uses a different trigger. By San Diego County climate zone:

The steep-slope rule has listed alternatives, such as at least R-38 ceiling insulation or a qualifying attic radiant barrier, and in CZ 10 and 14 a building with no ducts in the attic. Examples of zones: Coronado (92118) is CZ 7, Escondido and El Cajon are CZ 10, Julian (92036) is CZ 14, and Borrego Springs (92004) is CZ 15. Some ZIP codes straddle zones, so check the exact address with the CEC tool.

In the City of San Diego, Information Bulletin 123 says a re-roof needs a permit when framing, sheathing or other structural elements must be altered or replaced, when wood shakes or shingles or asphalt shingles are replaced with a material weighing more than six pounds per square foot, when skip sheathing is replaced with solid decking, or when the site is a designated historical resource or in a historic district. For single-family homes, duplexes and townhouses, damaged sheathing may be replaced in kind without a permit up to 25 percent of the roof surface. IB 123 also notes that re-roofing "may trigger" the Energy Code and that removing rooftop solar or equipment means a permit to reinstall it.

Plumbing and the sewer lateral

In the City of San Diego, stopping a leak or clearing a stoppage needs no plumbing permit, but replacing drain, soil, waste or vent pipe with new material does (SDMC § 129.0403(a)).

The City treats the whole sewer lateral as private property: the entire length, from the building to its connection with the City main under the street, is the owner's. Its handout puts maintenance (keeping the line clear of roots, grease and debris) and repair of a broken lateral on the owner. If the owner has lost all sewer service because of a total blockage or break in the section under the street, the City may correct it at no expense once the owner's plumber files a plumber's report; the City will not dig on private property, and it bills the owner when the cause is a lack of routine maintenance. We found no City of San Diego rule requiring a sewer lateral inspection when a property is sold; some other California cities have one, and a buyer may still ask for a sewer camera inspection. Other sewer agencies in the county set their own rules.

Heating and cooling

Replacing HVAC equipment is an alteration under Section 150.2(b)1 for single-family homes, duplexes and townhouses. Key points:

• Duct sealing. In all climate zones, replacing the air handler, the outdoor unit of a split system, or a coil triggers duct sealing confirmed by field verification and diagnostic testing. Exceptions: ducts already sealed and tested, duct systems under 40 linear feet, and ducts built, insulated or sealed with asbestos.
• Refrigerant charge verification. Required for heat pumps in all zones. For air conditioners it applies in CZ 2 and 8 to 15, so it applies in CZ 10, 14 and 15 but not in coastal CZ 7.
• Thermostats. Refrigerant-side work requires setback thermostats.
• Heat source. A replacement heating system may not use electric resistance as its primary heat source, with exceptions, including an existing electric-resistance system in CZ 7 or 15. The alteration rules do not require a heat pump when a gas furnace is replaced.
• Testing. A third-party ECC-Rater (formerly called a HERS Rater) does the field verification.

Buildings with three or more units fall under the multifamily section (180.2), which uses different numbers.

Refrigerants. EPA's May 2026 rule removed the January 1, 2026 federal installation date for certain pre-2025 equipment. California has its own refrigerant rules (CARB), so ask your licensed HVAC contractor what can be installed. Existing systems can keep running and be repaired, and EPA says a faulty component can be replaced with a similar component. Removing an old system requires refrigerant recovery by a technician with an EPA 608 Type II or Universal certificate.

Electrical

The 2025 California Electrical Code took effect January 1, 2026. Its residential amendments require a permit before installing or altering an electrical system, with narrow exemptions such as reinstalling attachment plug receptacles (not outlets) and replacing branch circuit overcurrent devices of the required capacity in the same location. The code also allows existing buildings to retain original materials and methods. California code does not require replacing a panel just because it is old; have a licensed electrician evaluate it, and replacement or alteration needs a permit.

What to inspect and document

• Roof: last re-roof date, number of layers, attic leak signs, flashing and gutters.
• Plumbing: pipe material where visible, water pressure, slow drains, any lateral camera video.
• Water heater: age, strapping (H&S § 19211), venting.
• HVAC: equipment ages, permit history, filters, whether ducts were ever tested.
• Electrical: panel amperage, permit history, tenant reports of flickering lights.
• Keep permits, invoices and photos by system in the property file.

These findings feed straight into your maintenance budget, and the work itself should go to licensed contractors.

For owners

When a tenant reports a roof leak, no heat or no hot water, treat it as a habitability item; the rules on timing and repair and deduct are on the habitability and repairs page, and urgent failures are covered in emergency repairs. Coastal owners should also read coastal maintenance for Coronado rentals, and owners of older homes in historic areas renting out a historic Coronado home.

McKee Properties manages rentals and runs an in-house maintenance division, Certified Property Maintenance; see maintenance services.

Local rules

Permit rules here are from the City of San Diego's Development Services Department and the County's Planning & Development Services, which covers unincorporated areas only. Coronado, Chula Vista, Oceanside and the county's other cities set their own, and sewer agencies outside the City of San Diego have their own lateral rules. In the City, re-roofs in a Very High Fire Hazard Severity Zone carry added fire rules for buildings built on or after August 27, 2009 (IB 123). Check your city's building department before work starts.

Frequently asked questions

Do I need a permit to re-roof a rental in San Diego?

In the City of San Diego, usually not, if the roof structure is not altered (SDMC § 129.0203(a)(16)); IB 123 lists the exceptions, such as structural work and historic sites. The unincorporated County has no re-roof exemption in PDS 110, and other cities set their own rules.

Does a new roof have to be a cool roof?

For a house, duplex or townhouse under the 2025 Energy Code, only when more than half the roof is replaced. Low-sloped roofs are covered in all four county zones; steep-sloped roofs in CZ 10, 14 and 15 but not coastal CZ 7, with listed alternatives such as R-38 ceiling insulation.

Who is responsible for the sewer line under the street?

In the City of San Diego, the owner. The City treats the entire lateral, out to the main under the street, as private property and the owner's to maintain and repair. The City may fix a total blockage or break in the street section at no charge after a plumber's report, unless the cause was lack of routine maintenance.

Does replacing an air conditioner require duct testing?

Usually, for a house, duplex or townhouse. In all climate zones, replacing the outdoor unit, air handler or coil triggers duct sealing verified by an ECC-Rater, unless an exception applies (ducts already sealed and tested, under 40 linear feet, or asbestos). Air conditioner refrigerant charge verification applies in CZ 10, 14 and 15, not CZ 7.

Must I replace an old electrical panel?

California code does not require replacing a panel just because of its age. Have a licensed electrician evaluate it; replacing or altering it needs a permit.

This is general information, not legal or tax advice. Rules change; confirm your situation with a California attorney, your local building or fire department, or a licensed professional.

Sources

• Civil Code § 1941.1 (opens in a new tab)
• Health and Safety Code § 19211 (opens in a new tab)
• 2025 Building Energy Efficiency Standards, Title 24, Part 6 (CEC-400-2025-010-F) (opens in a new tab)
• CEC 2025 Single-Family Residential Compliance Manual (opens in a new tab)
• CEC Energy Code Support Center: HVAC (opens in a new tab)
• CEC climate zone tool and maps (opens in a new tab)
• 40 CFR § 84.54 (opens in a new tab)
• EPA: Frequent Questions on the Phasedown of HFCs (opens in a new tab)
• CARB: Air-Conditioning Equipment (opens in a new tab)
• 2025 California Electrical Code amendments (BSC) (opens in a new tab)
• San Diego Municipal Code Ch. 12, Art. 9, Div. 2 (opens in a new tab)
• San Diego Municipal Code Ch. 12, Art. 9, Div. 4 (opens in a new tab)
• City of San Diego Information Bulletin 103 (opens in a new tab)
• City of San Diego Information Bulletin 123 (opens in a new tab)
• City of San Diego Development Services FAQs (opens in a new tab)
• City of San Diego: Sewer Laterals (opens in a new tab)
• County of San Diego PDS 110 (opens in a new tab)
• County of San Diego PDS 641A Re-Roof Referral Sheet (opens in a new tab)

Verified October 19, 2026.