A deep dive into new proposed changes for energy efficiency in Part 9. We will explain all energy efficiency and GHG related changes for Part 9 – regardless of whether they are going to the 2023 fall public review or the winter 2024 public review. We will talk about the new prescriptive trade-off points system for tiers 3, 4 and 5 and the prescriptive packages for tier 5. We will also go over the changes to airtightness, solar heat gain coefficients and new energy use metrics, before delving into the proposed greenhouse gas requirements. At the end, we will repeat the tips on how to submit effective comments for national codes  public reviews.