The Electrification Standard

We must move away from fossil fuels and electrify our buildings for a safe and healthy future. Yet, as we push to electrify everything supplied by 100% renewables, traditional primary energy and CO2-equivalent emissions measures–including conventional “net zero” goals–are inadequate for assessing a building’s performance and effectiveness.

Consequently, the Passive House Institute (PHI) and the Passive House standard measure a building’s performance within a fully renewable energy context using a metric called Primary Energy Renewable (PER), which utilizes Primary Energy Renewable factors (PER Factors). PER clarifies that the renewable resources required to meet a building’s final energy demand must factor in losses associated with distribution and storage if we are to optimize resource efficiency.

With a focus on efficiency, the PER system challenges us to optimize building performance to support integration into a 100% renewable future. It produces “grid-friendly” buildings.

To do this, it emphasizes the importance of synchronizing energy demand with renewable supply. It acknowledges the complexities of seasonal energy disparities and advocates for building designs that reduce energy use during periods of limited renewable availability. So, rather than viewing energy assessments merely as a means of balancing supply and demand as one does with “net zero,” the PER framework provides a more nuanced perspective that includes local climate considerations, specific energy applications, and the broader goal of energy resource conservation.

Conventional “net zero” misaligns supply and demand, distorting our understanding of resource efficiency. Passive House PER optimally tunes the building demand and renewable supply.

Passive House provides the basis for understanding the complex relationship of renewable supply, demand, and short-term and long-term storage losses to optimize resource efficiency with “grid-friendly” buildings.

PHI determined PER factors for electricity by simulating hourly energy demand profiles within a scenario where energy is supplied exclusively from renewable sources, including required short and long-term storage. Using climate data from diverse regions, the generated PER factors quantify the additional renewable energy needed to offset the final energy consumed by a building, accounting for all associated losses. For instance, a PER factor of 1.5 indicates that an additional 50% of renewable primary energy must be produced to satisfy the building’s energy demand.

On the other hand, a traditional “net-zero” calculation simply offsets annual supply and demand, not indicating the true cost but instead externalizing it. For this reason, PHI (and the logic of resource efficiency driving PER) also separates the demand and supply evaluation. Demand is rated by PER limits based on floor area; however, supply is judged based not on offsetting total usage but on how well it utilizes the plot of earth the building is occupying – or the projected footprint of the building. In decoupling supply and demand, taller buildings are not penalized, and production is not rewarded for production’s sake.

Renewable generation is not evaluated by offsetting demand but by optimally utilizing the earth’s surface resource on which the building sits.

So, no matter if the renewable supply and storage is coming from the site or the utility, the PER factor emphasizes the simultaneity of renewable energy resource availability and consumer demand, as this interplay determines the amount and type of storage needed. The necessity for short-term versus seasonal storage impacts efficiency, with shorter storage durations being better. Heating during periods of low renewable energy availability demands significant energy resources, while cooling can frequently utilize the available energy more directly, minimizing storage needs. Various energy types—including household electricity, domestic hot water, heating, and cooling—require distinct load profiles, which inform the overall energy demand framework. The examination of regional PER factors underscores variability influenced by local climate conditions. Notably, locations with robust hydropower resources typically exhibit lower PER factors due to the consistent availability of energy.

The PHI certification levels can exclude renewable generation (Low Energy Building & Classic) or include renewable generation (Plus & Premium). All lock-in fundamental high-quality Passive House performance. Plus & Premium certifications are also available for the retrofit EnerPHit standard.

By understanding the relationship between energy supply and demand through the PER factors, PHI’s framework empowers architects, engineers, and policymakers to optimize the resource efficiency of buildings. Passive House is an electrification standard (along with a health and comfort standard) grounded in the responsible management of renewable energy resources.

Are you ready to take control of the energy transition? Learn more about becoming a Certified Passive House Designer. Our Spring Cohort kicks off on April 9th, but you can register today and gain immediate access to course materials.

Learn more about PER here.