How Much Does Air Duct Replacement Cost in San Francisco? [2025 Data]

In San Francisco, where historic architecture meets modern retrofits, air duct replacement is a common project for improving comfort and efficiency. Leaky or undersized ducts may contribute to higher Bay Area energy bills. On average, air duct replacement in San Francisco costs $1,964, with most homeowners paying between $886 and $3,159. Your final cost depends on your home’s size, duct material, and the difficulty of accessing your ductwork.

Air Duct Replacement Cost Factors 

San Francisco’s housing stock—from pre-war Victorians to newer condos—means air duct replacement costs can vary widely. Older homes may require more demolition and patching, while newer builds may have ducts in easier-to-access attics. Climate may also play a role: with cool, damp winters and mild summers, ducts often need to be sealed and insulated to prevent moisture and mold.

Size

The size of your home directly affects air duct replacement costs. Larger homes require more materials and labor to replace the entire duct system. On average, the cost ranges from $2,000 to $5,000 for a small- to medium-sized home. However, duct replacement can run as low as $1,400 for smaller homes and as high as $9,000 for larger homes. Here’s how the size of your home affects duct replacement costs:

Duct Location

If only specific sections of your ductwork need replacement, such as in a renovation project, costs will depend on the location of the damaged or worn ductwork. Replacing ducts in hard-to-reach or concealed areas—like attics, basements, ceilings, walls, or crawl spaces—can increase labor costs. Here’s how the location of the ducts could affect their cost:

Duct Material

The material you choose for your replacement ducts affects both their cost and longevity. Flexible ducts are often used in San Francisco for tight retrofits, while sheet metal is often preferred in new construction for its durability and efficiency.

Sheet metal ducts are durable but pricey. Flexible ducts, on the other hand, are more affordable but may need to be repaired or replaced sooner. Here’s a breakdown of air duct replacement costs based on duct material:

HVAC Pro Costs

Duct replacement often requires a small crew and may take one to three days, depending on your home’s size, age, and layout.

Older homes in the Mission, Haight-Ashbury, or Inner Richmond may have ducts concealed behind plaster walls, which can extend labor hours. Condos or newer builds in SoMa and Mission Bay often have more accessible systems, making the job quicker. Because costs can vary widely, most contractors in the Bay Area provide in-person inspections before giving a detailed estimate.

Labor Costs

Most San Francisco HVAC pros charge $85 to $135 per hour, with service calls starting at about $125. Labor time may increase in multi-story homes or in historic properties where ducts are hidden behind finishes. Summer and winter demand spikes can also influence availability and scheduling.

Permits and Regulations

The San Francisco Department of Building Inspection (DBI) typically requires a mechanical permit for duct replacement or modification. Permit fees start around $100 to $150, but can vary with project scope. These permits help ensure work complies with local codes and California’s Title 24 energy efficiency standards. Skipping permits may lead to problems with inspections or resale.

Licensing and Insurance

California requires HVAC contractors to hold a C-20 Warm-Air Heating, Ventilating, and Air-Conditioning license issued by the Contractors State License Board (CSLB). Licensed contractors are also required to carry liability insurance, and reputable Bay Area companies often carry workers’ compensation coverage as well. Homeowners may want to verify a contractor’s license through the CSLB before hiring.

Local Climate Considerations

San Francisco’s foggy summers and damp winters make ductwork especially prone to condensation and mold. Homes with ducts in crawl spaces under Victorians or basements may face these issues. Local contractors often recommend sealing ducts with mastic and wrapping them in insulation to protect against moisture and reduce energy loss.

Additional Pros to Consider Hiring

Air duct replacement projects in San Francisco may require more than just an HVAC crew, especially in older or multi-unit buildings. Depending on your home’s age and layout, you might also need:

• General contractors: For demolition and finish work when ducts are concealed behind walls or ceilings, which is common in Victorian and Edwardian homes.

• Insulation contractors: To wrap ducts running through unconditioned basements or crawl spaces, improving efficiency and helping to prevent condensation.

• Mold remediation specialists: San Francisco’s damp climate can create dirty air ducts along with conditions for mold in crawl spaces or basements, which should be addressed before ducts are replaced.

• Electricians: In multi-family buildings or homes with complex layouts, ducts may run near wiring and require electrical adjustments for safe installation.

• Asbestos abatement teams: Many pre-1980 homes in San Francisco may contain asbestos insulation around ducts. If present, it must be removed by a licensed professional before ductwork can be replaced.

Does Air Duct Replacement Increase Home Value?

Air duct replacement may not directly increase a home’s appraised value, but it can make San Francisco properties more attractive to buyers. With the city’s high energy costs, efficient ductwork is often a selling point, especially in older homes where systems may be outdated. Buyers in neighborhoods such as Noe Valley or the Marina may view updated ducts as reassurance that comfort, air quality, and energy efficiency have already been addressed.

How Angi Gets Its Cost Data

Home is the most important place on earth, which is why Angi has helped more than 150 million homeowners transform their houses into homes they adore. To help homeowners with their next project, Angi provides readers with the most accurate cost data and upholds strict editorial standards. We survey real Angi customers about their project costs to develop the pricing data you see, so you can make the best decisions for you and your home. We pair this data with research from reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects. 

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