"The requirement allows ""an equivalent computation procedure"". The burden of proof lies with the project team to demonstrate to the Green Rater and Provider’s satisfaction that a methodology is considered ""equivalent"". Here are a few guidelines:
• Any sizing approach should include inputs that are based on the specifics of the home, such as solar gains from windows, duct losses, envelope leakage and insulation levels, etc.
• Some tools are “powered by ACCA Manual J” and have a logo to indicate this.
• If the Green Rater or Provider is uncertain, both approaches (the proposed approach and ACCA Manual J) should be used to determine equivalence."