Blower Door Testing

ECC / HERS Blower Door Verification in Northern California

Blower door testing is one of the most important field verifications required under the California Energy Code.

It measures how airtight a building’s envelope is and determines whether the structure meets energy efficiency standards required for permit approval and final inspection.

Pacific Airflow provides certified ECC / HERS blower door verification for contractors, builders, and homeowners throughout Northern California.

When Is a Blower Door Test Required?

Blower door testing is required for:

  • Residential new construction

  • Multifamily new construction

  • Additions and alterations that trigger envelope verification

  • Projects requiring ECC / HERS documentation for permit closeout

Passing this test is required before a project can receive final sign-off from the building department.

2025 Code Update — Multi-Point Blower Door Testing

Under the 2025 ECC code, a Multi-Point Blower Door Test is now allowed in addition to the traditional single-point test.

This means:

  • Digital testing using calibrated equipment

  • Multiple pressure readings between 10–60 Pascals

  • GPS-verified testing location

  • More accurate real-world leakage measurements

  • Less guesswork and tighter verification

This is a major upgrade to how building airtightness is measured.

What Is a Blower Door Test?

A blower door test uses a calibrated fan installed in an exterior doorway to pressurize or depressurize the building.

This allows us to measure how much air is leaking through:

  • Wall penetrations

  • Framing connections

  • Top plates and bottom plates

  • Attic and crawlspace connections

  • Windows and doors

  • Electrical and plumbing penetrations

The equipment includes:

  • Calibrated blower door fan

  • Precision manometer

  • Sealed test setup per RESNET 380 standards

  • Digital test recording and verification

This is not a “smoke test.” It is a measurable, code-recognized verification of building airtightness.

Why Airtightness Matters

Poor building envelope sealing causes:

  • Higher heating and cooling bills

  • Drafts and uneven temperatures

  • Moisture intrusion and condensation

  • Mold and mildew risk

  • Poor indoor air quality from attic or crawlspace air

  • Excess strain on HVAC systems

You only get one chance to build the envelope correctly. Once drywall and siding are installed, fixing leakage becomes extremely difficult.

ECC / HERS Certified Verification

As a certified ECC Rater, Pacific Airflow performs blower door testing that is:

  • Registered with the ECC Provider (CHEERS)

  • Accepted by all Northern California building departments

  • Performed according to California Energy Code and RESNET 380 standards

  • Required for permit final and inspection approval

This is official code compliance documentation.

What Happens If the Home Fails?

If the building fails:

  1. Leakage locations are identified

  2. Sealing corrections are made

  3. The building is retested

  4. Passing results are registered for inspection

We work directly with builders and contractors to quickly identify problem areas so they can be corrected efficiently.

Serving Northern California Builders and Contractors

Pacific Airflow provides blower door testing for:

  • Single family homes

  • Multifamily projects

  • Additions and alterations

  • Projects requiring ECC / HERS verification

We make the process simple, fast, and inspection-ready.

Schedule Your Blower Door Test

If your project involves new construction or envelope verification, this test will be required before final sign-off.

Pacific Airflow is your local ECC / HERS testing partner for compliant blower door verification across Northern California.

Contact us today to schedule your test.