PHIUS has released its new certification requirements (PHIUS 2021 Core and PHIUS 2021 Zero). There are critical changes that building owners and developers in New York City should be aware of. Notable updates include:
- Adjusted heating/cooling requirements;
- Adjusted primary energy requirement;
- Adjusted source energy coefficient;
Under the previous PHIUS guidelines (PHIUS 2018), dense multifamily buildings, such as affordable and senior housing, had a more difficult path to compliance due to smaller unit sizes and a more significant share of studios that increase occupant density. Well-designed density is widely considered a net positive because it allows for shared infrastructure and resources. But, the previous PHIUS standards ostensibly punished dense, multifamily buildings because they did not account for increased cooling, heating and annual energy demand because of the higher occupancy density. The previous standard resulted in more insulation, costly MEP equipment, and larger solar photovoltaic arrays, which sometimes deterred building owners from certifying to the PHIUS standard.
The 2021 PHIUS guidelines account for the increased heating, cooling, and energy loads on denser buildings. PCA modeled our affordable housing buildings that are not pursuing PHIUS certification but designed using the Passive House principles. We compared the modeled performance of this building with the 2018 PHIUS and the 2021 PHIUS Core requirements. Across the board, the 2021 standards are less complicated for the building to reach, potentially resulting in savings on windows, insulation, and MEP equipment.
Above: Comparing a Multi-Family Affordable Housing building's heating and cooling performance to 2018 and 2021 PHIUS standards.
In addition to the adjustment on heating and cooling demand and loads, PHIUS 2021 makes two critical adjustments to Primary Energy Demand:
1) PHIUS adds an adjustment for dense multifamily buildings
2) PHIUS also uses the National Renewable Energy Laboratory (NREL)'s 2050 projection for the source energy coefficient instead of the current EPA source energy coefficient. Our source energy demand would also be reduced because the new standard uses a much cleaner future electric grid. See below.
Above: Comparing a Multi-Family Affordable Housing building's primary energy performance to 2018 and 2021 PHIUS standards.
The PHIUS 2021 standard gives owners and developers much greater flexibility on compliance and whether solar is provided (and how much solar is provided) on their projects.
We are excited for the potential that PHIUS 2021 presents. The new standards removes barriers in providing best-practice energy efficiency in all buildings, especially in affordable housing.
If you or your team have questions on PHIUS 2021 and how it relates to your projects, please feel free to reach out to our team to discuss.
Paul Castrucci: [email protected]
Grayson Jordan: [email protected]