Session · Policy and codes · Designers and consultants · Policymakers and advocates

Multifamily Buildings Energy Standards Report

Marine Sanchez, RDH Building Science; with Bronwyn Barry · September 9, 2026 · PHN Presents

One 31-unit apartment building modeled under the IECC, ASHRAE 90.1, PHI Classic, PHI Low Energy Building, and Phius in climate zones 1 to 7, normalized to a common basis: Passive House cut heating and cooling demand and total energy two- to four-and-a-half-fold.

Key points

• The differences between the IECC, ASHRAE, Phius, and PHI standards.
• How Passive House standards compare with code minimum and other performance pathways.
• The workflow for translating Passive House models to hourly simulation for a fair comparison.
• How the choice of software and protocol affects reported results.

Downloads

• The report