Air Leakage

The 2018 IRC/IECC require comprehensive air sealing to minimize heat loss and reduce the potential for moisture condensation issues.

Air Leakage Points Drawing

Inspection of the installation of all necessary details must be documented AND a post-construction blower door test must be completed to verify that the house has an acceptable leakage rate, as measured in Air Changes per Hour (ACH) at the test pressure of 50 pascals.

The 2018 IECC specifies a maximum air leakage rate of 3 ACH in the PA Climate Zones.

(Prior to 2020, an amendment in the PA Rules and Regulations increased the maximum allowable air leakage limit to 5 ACH, but this was not included in the new regulations, so the new lower limit of 3 ACH applies to dwellings following any compliance path, including the RAEP.)

Air Changes per Hour:

The number of times the full volume of air in the house flows out and is replaced with outdoor air flowing in during a one hour period.
Calculated by measuring the leakage rate (in cubic feet per minute - CFM) in the house with a blower door, converting it to cubic feet per hour, and dividing it by the house volume (in cubic feet).
ACH = (CFM x 60) / Volume

The list of required air sealing details is too extensive to cover on this website. However, this document, available from the US DOE Building Energy Codes Program, is a good starting point:

Third Party Evaluation

The 2018 IRC/IECC gives the local code official the option to require that air sealing inspections and blower door testing be completed by an "approved third party"

Approval of third parties is at the discretion of the local code official. In most cases, certification by one of the following organizations will be required:

Local Energy Audits Interested in Air Leakage Services?

(484) 443-1010