Multifamily Resource Center



The PHIUS+2015 Passive Building Standard released by Passive House Institute US (PHIUS) in 2015 is the first and only passive building standard in the world based upon climate-specific comfort and performance criteria aimed at presenting an affordable solution to achieving the most durable, resilient, and energy-efficient building possible for a specific location. Despite its name, PHIUS standards are not limited to houses but can be applied to buildings of all use types. Buildings designed and built to the PHIUS+ 2015 Standard consume 86% less energy for heating and 46% less energy for cooling (depending on climate zone and building type) when compared to a code-compliant building (International Energy Conservation Code IECC 2009).

The cost-optimized PHIUS+2015 Standard is spurring new growth in passive buildings from coast to coast, with the most significant gains coming from the multifamily housing sector. Certified and Pre-Certified PHIUS+ projects now total more than 1 million square feet across 1,200 units nationwide. As more units come online everyday, more families are enjoying the affordability, resiliency, and health benefits of passive buildings.

PHIUS+2015 Overview

The PHIUS+2015 Passive Building Standard exceeds the requirements of Energy Star and other US standards and programs; in fact, the US Department of Energy is now promoting PHIUS+ project certification as the highest attainable level of energy efficiency.

Buildings built to this standard have optimized envelopes which are airtight and superinsulated, high-performance windows, and balanced heat-recovery ventilation systems that produce exceptionally high levels of air quality and thermal comfort. Certification of the completed building is contingent upon verified performance and building energy metrics. The result is a building that is not just comfortable, healthy, durable, and super energy efficient, but also extremely resilient in the face of natural disasters and climate change.  



PHIUS+2015: the Best Pathway to Zero Energy

Since the PHIUS+ methodology delivers buildings that require very little energy to operate (low energy use intensity), these projects provide a great pathway toward energy independence and carbon reduction targets in order to achieve a more resilient and sustainable future. The cost-optimized, climate-specific PHIUS+2015 Passive Building Standard provides the best path toward achieving the healthiest, most comfortable, and most cost-effective path to zero energy, zero carbon, and beyond.

Passive buildings are not to be confused with zero energy buildings, however the PHIUS+ certification program requires all projects to be zero energy ready per the guidelines of the DOE Zero Energy Ready Home program. A zero energy ready building means that the project could go off the grid with the addition of a modest onsite renewable energy system or the purchase of renewable energy from a utility. Onsite renewable energy systems can either be incorporated during initial construction or added on at a later date.