Compare when testing is required, which passing limits apply, and the key difference between New Jersey and Pennsylvania for new residential construction.
Code summary reviewed September 2026. Permit dates, approved plans, compliance paths, and the local enforcing agency determine the requirements for each project.
New Jersey adopted the 2024 IECC on August 17, 2026. During the six-month grace period, a complete permit application may still be reviewed under the previously adopted 2021 IECC.
The New Jersey limits shown below apply to projects governed by the 2021 IECC. Confirm the approved code edition before testing.
*When the applicable state code requires a test, the requirement does not disappear because a municipality fails to request or enforce it.
Permit dates, approved plans, and compliance paths may affect individual projects. See our FAQ: What if the municipality does not require testing?
Compare blower door and duct leakage test requirements, passing limits, and key differences between New Jersey and Pennsylvania for new residential construction.
Learn more about Blower Door Tests Here
New Jersey still requires duct leakage testing when all ducts and the air handler are inside the building thermal envelope. In that situation, the maximum permitted leakage is 8.0 CFM25 per 100 square feet of conditioned floor area.
Pennsylvania does not require a duct leakage test when all ducts and air handlers are entirely inside the building thermal envelope. The same HVAC layout can therefore require testing in New Jersey while qualifying for an exception in Pennsylvania.
New Jersey requires both a blower door and duct leakage test for covered new residential construction. Duct leakage testing may be completed during rough-in or after construction.
New one- and two-family homes and townhouses governed by New Jersey’s residential energy code must pass at 3.0 ACH50 or lower. The test must be performed by a person independent of the installer.
Pennsylvania’s current Uniform Construction Code adopts the 2021 IECC with state-specific amendments. The project’s contract and permit dates, approved compliance path, and HVAC layout determine which requirements apply.
New one- and two-family homes and townhouses governed by Pennsylvania’s current UCC must pass a blower door test at 3.0 ACH50 or lower.
A duct leakage test is required unless all ducts and air handlers are entirely inside the building thermal envelope. A separate exception applies to ducts serving a heat-recovery or energy-recovery ventilator when those ducts are not integrated with the heating or cooling system.
ANSI/RESNET/ICC 380-2019
Standard referenced by the 2021 IECC for conducting duct-leakage testing.
BPI Infiltration & Duct Leakage Certification
Professional certification held by Keystone’s tester for blower-door and duct-leakage testing.
Send the project address, permit date, approved energy-code documents, and HVAC scope when scheduling. Keystone will confirm the test scope and readiness requirements before the appointment.