Diagnostic Testing for Code Compliance

New York's Energy Conservation Construction Code (ECCCNYS) requires that every new residential building pass a blower door test before a Certificate of Occupancy can be issued. If your home doesn't meet the required air leakage standard, you can't close on the build — it's that simple.

Duct blaster testing is also required for HVAC duct systems to verify that conditioned air is reaching the rooms it's supposed to — not leaking into your attic, walls, or crawl space. Leaky ducts can account for up to 25% of total home energy loss.

At Energy Efficiency Experts, we perform both blower door and duct blaster testing for builders, general contractors, and homeowners across Westchester County, New York City, and surrounding areas. Our testers are BPI-certified and use calibrated, industry-standard equipment. We provide same-day results and a written report your building inspector can use to sign off on your project.

Whether you're building a new home, completing a major renovation, or need testing for an energy incentive program — we'll get you the readings you need, fast.

Testing at a Glance

3.0
ACH50 — NY maximum air leakage for new construction
4 CFM
per 100 sq ft — NY maximum duct leakage at rough-in
CO
Required to pass before Certificate of Occupancy is issued
BPI
Certified testing professionals

When Is Testing Required?

If you're building or renovating in New York, chances are you need a blower door test

🏗️

New Construction

The NY Energy Conservation Code requires a blower door test for every new residential building — single-family homes, duplexes, and 1–4 family buildings. No exceptions. Your home must test at or below 3.0 ACH50 before a Certificate of Occupancy will be issued.

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Renovations & Additions

Thermally isolated additions — additions with their own separate heating/cooling zone — must meet the same air sealing standards as new construction. If your addition has its own building envelope, it needs to be tested before you can get your CO.

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Certificate of Occupancy

No passing blower door test means no Certificate of Occupancy. Your code enforcement official will require a written test report before signing off. If the building fails, it must be sealed and retested until it passes — we can help with both.

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Energy Programs

Many energy incentive programs — including NYSERDA EmPower+, Comfort Home, and Con Edison Weather Ready — require pre- and post-work diagnostic testing to verify the improvements made. We provide the testing these programs require.

Blower Door Testing

A blower door test measures the overall airtightness of your building's thermal envelope — how much air leaks through gaps, cracks, and penetrations in the walls, roof, foundation, windows, and doors that separate the inside of your home from the outside.

How it works: We mount a calibrated, variable-speed fan into an exterior doorway using an adjustable frame. All exterior doors and windows are closed, and all interior doors are opened. The fan depressurizes the house to 50 Pascals — drawing outside air in through every gap and crack in the building envelope.

A digital manometer measures the airflow required to maintain that pressure, and the result is expressed as ACH50 — air changes per hour at 50 Pascals. This tells you exactly how many times the entire volume of air in the home is replaced per hour at test pressure.

New York requires a maximum of 3.0 ACH50 for new residential construction in Climate Zones 4A and 5A (NYC metro, Westchester, Hudson Valley). Under the 2025 code, Climate Zone 6A (northern NY) requires 2.5 ACH50.

Common Air Leak Locations We Find

  • Attic hatch and attic floor penetrations
  • Basement rim joist and sill plate
  • Around recessed light fixtures
  • Plumbing and electrical penetrations
  • Around window and door frames
  • Fireplace dampers and chase
  • HVAC register boots
  • Crawl space walls and vents

Duct Blaster Testing

A duct blaster test measures the airtightness of your HVAC duct system — how much conditioned air leaks out of supply ducts or how much unconditioned air leaks into return ducts before reaching the rooms it's intended for.

How it works: We seal all supply and return registers with tape or adhesive covers, then connect a calibrated duct blaster fan to the duct system through a register opening or the air handler. The fan pressurizes the duct system to 25 Pascals, and we measure the airflow in CFM25 — the cubic feet per minute of air leaking out at test pressure.

New York code requires that total duct leakage not exceed 4 CFM per 100 square feet of conditioned floor area when tested at rough-in. Post-construction, the limit is 8 CFM per 100 square feet.

Duct leakage testing is required for all new duct systems unless the ducts and air handler are located entirely within the building's conditioned space. If any portion of your ductwork runs through an attic, crawl space, or unconditioned basement, testing is required.

When Duct Testing Is Required

  • Ducts run through unconditioned attic
  • Ducts run through unconditioned basement
  • Ducts run through crawl space
  • Ducts run through garage or exterior walls
  • New HVAC system installation
  • Energy program pre/post verification

New York Code Requirements

Under the NY Energy Conservation Construction Code (ECCCNYS), these are the standards your building must meet

🏠 Blower Door — Air Leakage

3.0 ACH50

Maximum air leakage rate for new residential construction in Climate Zones 4A & 5A (NYC, Westchester, Hudson Valley, Western NY). Under the 2025 code, Zone 6A (northern NY) tightens to 2.5 ACH50.

📋 Required for all new residential buildings. Must pass before Certificate of Occupancy is issued. Written report required for code enforcement.

🌀 Duct Blaster — Duct Leakage

4 CFM

Maximum duct leakage per 100 sq ft of conditioned floor area at rough-in (25 Pa). Post-construction limit is 8 CFM per 100 sq ft. Exempt only if ducts are entirely within conditioned space.

📋 Testing per ANSI/RESNET/ICC 380 or ASTM E1554. The 2025 code introduces stricter limits for ducts in attic spaces (1.5 CFM/100 sq ft).

How the Process Works

Fast, professional, and built around your project timeline

1

Schedule

Contact us to book your test. We work around your construction schedule and can often accommodate same-week requests.

2

On-Site Testing

We bring calibrated blower door and duct blaster equipment to your site. Testing typically takes 1–2 hours depending on building size.

3

Results & Report

You get same-day results on-site plus a written report with ACH50, CFM50, and all data your building inspector needs to sign off.

4

Pass or Remediate

If you pass, the report goes to code enforcement. If not, we pinpoint the leaks and can help seal them — then retest until you're compliant.

Need a blower door or duct blaster test for your project? Contact us to schedule — we serve Westchester, NYC, and surrounding areas.

Schedule a Test

Frequently Asked Questions

When is a blower door test required in New York?

A blower door test is required for all new residential construction — single-family homes, duplexes, and 1–4 family buildings — before a Certificate of Occupancy can be issued. Thermally isolated additions to existing buildings must also be tested. General renovations that don't affect the building's thermal envelope do not require testing.

What ACH50 do I need to pass?

Under the current NY Energy Conservation Code, the maximum allowable air leakage is 3.0 ACH50 for Climate Zones 4A and 5A, which covers the NYC metro area, Westchester, the Hudson Valley, and Western New York. Under the 2025 code, Climate Zone 6A (northern New York) requires 2.5 ACH50.

How long does the testing take?

A blower door test typically takes about 1 hour. If duct blaster testing is also needed, allow 1.5–2 hours total. We provide results on-site the same day, along with a written report for your building inspector or code enforcement official.

What happens if my building fails the blower door test?

If your building exceeds the maximum allowable air leakage rate, it must be sealed and retested until it passes. During the test, we use smoke pencils and other diagnostic tools to pinpoint exactly where the leaks are — so you know exactly what needs to be addressed. We also offer insulation and air sealing services and can help you get the building to pass.

Do I also need a duct blaster test?

Duct leakage testing is required for new duct systems unless the ducts and air handler are located entirely within the building's conditioned space. If any ductwork runs through an attic, crawl space, unconditioned basement, or garage, testing is required. We can perform both tests in a single visit.

Can you help me fix air leaks if I fail?

Yes — air sealing and insulation are core services we offer. If your building fails the blower door test, we can identify the leaks during testing, perform the air sealing work to bring it into compliance, and then retest. We're a one-stop shop for both testing and remediation.

What areas do you serve?

We serve Westchester County, New York City (all five boroughs), and surrounding areas including Rockland County, Putnam County, and the lower Hudson Valley. Contact us if you're unsure whether we cover your area — we're happy to discuss your project.

Need Code-Compliant Testing for Your Project?

Schedule your blower door or duct blaster test today. Same-day results, written reports, and expert remediation if needed.

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