Pennsylvania’s new building code envelope and insulation requirements became effective October 1, 2018. The biggest changes were adopting the Energy Rating Index (ERI) compliance path (with the option to use 2009 IECC minimum insulation levels as a backstop); thermal envelope requirement of the 2015 IECC; and new options for buried ducts in a vented attic.

Buried ducts consist of heating and cooling ductwork that is installed in a vented attic but buried in the ceiling insulation. The new code language outlines both deeply buried ducts and ducts considered to be inside conditioned space. For more information on the requirements for buried ducts, see sections R403.3.6 and R403.3.7 of the 2018 IECC, contact your local building department, or review the recent TechSpec report.

Overview of Pennsylvania’s Building Code Envelope Changes

  • R-values and U-factors have been improved for wood framed walls, ceilings, and below-grade walls.
  • U-factors and the Solar Heat Gain Coefficient have been improved for windows and skylights.
  • The requirements now include an option for ducts buried within ceiling insulation.
  • The air leakage target has been improved and testing is mandatory. The building envelope must meet a tested air exchange rate of 5 ACH50.

What is the Energy Rating Index?

The ERI provides a new path for energy code compliance. Builders using this path need to achieve a certain score, on a scale from 0 to 100, to achieve energy efficiency code compliance for building construction. A lower score means a more energy efficient home, and certified software must be used to determine code compliance. The score of 100 aligns with the 2006 IECC model code.

In Pennsylvania, the target score is 61 in Climate Zones 5 and 6, and 62 in Climate Zone 4.

There are two distinctions for builders using the ERI path:

  • The ERI path is distinct from the Home Energy Rating System (HERS index scale) since other approved home rating programs could, in theory, be used for ERI compliance.
  • Both HERS and ERI allow for the use of renewable energy to reduce scores, however, ERI includes provisions to ensure that renewable energy does not replace more permanent or reliable energy efficiency measures. As a matter of practice, the ERI path calls for builders to use HERS to demonstrate building code compliance. Therefore, if the ERI path is used for energy code compliance and renewable energy is incorporated, builders must construct a building envelope that meets the prescriptive envelope requirements of 2015 IECC.

To view a listing of key changes to the 2015 Pennsylvania Uniform Construction Code insulation requirements, download the detailed summary.

This summary is offered for informational purposes only. It does not purport to be an exhaustive analysis of code changes or provide advice that will ensure guaranteed compliance with any energy code provision. Please consult with local authorities before finalizing your installation plans.

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