New York City Takes Significant Step Toward Electrification

New York City is about to be one step closer to total electrification.

The New York City Council has enacted a bill, which current Mayor DeBlasio will sign, that will ban the use of natural gas hookups on a substantial number of new buildings in the coming years. The ban will apply to all new construction seven stories and shorter starting in December 2023 and for buildings taller than seven stories starting in 2027. 

New York City as seen from 425 Grand Concourse, a Phius project in the Bronx, New York

New York City as seen from 425 Grand Concourse — a Phius project in the Bronx

There are exceptions to the new law, including: multifamily buildings in which more than 50 percent of residents are low-income, some manufacturing facilities, laundromats, crematoriums, hospitals, and commercial kitchens. 

Despite the exceptions, this law will apply to a substantial number of new buildings. From a Phius perspective, this new law is in line with the new prescriptive path for the Phius CORE standard and the Phius ZERO standard which prohibits the use of fossil fuels. Even for projects that do not choose the above standards (projects pursuing the performance path under Phius CORE can use fossil fuel combustion appliances), an increasing number are opting to go all-electric. New York City joins other major cities including Seattle, Sacramento and San Jose in enacting policies restricting the use of natural gas in the built environment. 

Finally, the legislation also mandates two studies: one on the use of heat pumps and a second on the legislation’s impact on the electrical grid. The legislation, however, does not apply to existing buildings.

This new law is part of a larger electrification effort within both the City and State. Members of the New York State Assembly have introduced legislation that would prohibit towns and cities across the state from allowing new natural gas hookups. Exceptions to this requirement would require a project to show that an all-electric approach is either physically or technically infeasible (detailed rules determine infeasibility). Moreover, New York City Housing Authority (NYCHA), New York State Energy Research and Development Authority (NYSERDA) and the New York Power Authority (NYPA) are funding a challenge to space heating manufacturers ($263 million) to develop new products designed for existing multifamily buildings with the aim to spur the electrification market in this important sector. This effort moves in parallel with the heat pump study requirement in the New York City law. 

As we all work together to decarbonize the built environment, we look forward to reporting on many more similar policies in the coming months and years.

Does Your Job Require You to Choose or Spec Windows? We Want to Hear From You!

Michael FrancoIn this week’s blog post, Phius Product Certification Manager Michael Franco breaks down the challenges of choosing the right windows for passive house projects and invites you to our upcoming roundtable event to discuss what data points are most important when selecting windows.

A sample color infrared result from LBNL THERM software. This software tool allows practitioners to model 2D heat transfer between building components (in this case, how a window frame, its spacer, and glazing package interact as seen via a cross-section at the sill area). The left-hand side of the image represents the outside-facing portion of the window, while the right-hand side is the indoor portion. For the purposes of this visualization, red is warm, purple is cold. Heat is shown moving through this window assembly in the direction of red to purple (from inside the building toward the outside area).

A sample color infrared result from LBNL THERM software. This software tool allows practitioners to model 2D heat transfer between building components (in this case, how a window frame, its spacer, and glazing package interact as seen via a cross-section at the sill area). The left-hand side of the image represents the outside-facing portion of the window, while the right-hand side is the indoor portion. For the purposes of this visualization, red is warm, purple is cold. Heat is shown moving through this window assembly in the direction of red to purple (from inside the building toward the outside area).

Windows are critical to the function of any building, especially a passive one. We as building occupants and passive building practitioners have come to expect a lot from these transparent feats of engineering.

Our windows must let in light, but also the right amount of heat from the sun. Depending on the climate of residence, the “right amount of heat” may be as little as possible. Windows in climates with long cooling seasons are often asked to reflect a significant portion of the heat that is packaged together with the sunlight we need.

We also expect windows and doors to keep outside air outside, except for when we change our minds, enter, or leave the building. Whether they swing, slide, tilt or turn, these operable envelope components must find a way to properly seal against outside air. On top of this task, windows and doors must mitigate energy losses via thermal bridging despite their often more complex frame profiles – quite a tall order since we cannot sacrifice outside air or egress on demand.


All of these considerations factor into performance. For example, in order to meet the demands of a passive building energy model, a CPHC
® (Phius Certified Passive House Consultant) or energy modeler must understand a window’s thermal performance at the component level. To accurately predict how a fenestration product will perform, the practitioner needs specific thermal performance values for the product’s frame, spacer, and glass in order to calculate how much heat will escape annually via the glass itself and the contact points between the wall, frame, spacer, and glass when the product is installed at actual size.

This requirement is why center-of-glass performance values alone or whole-window performance values at a standard size are insufficient to understand a window’s thermal performance in an actual product. A window’s performance does not scale simply or linearly if someone were to take a whole-window performance value at a standard size and attempt to scale it up or down to the size their project requires. The ratio of frame to glass heavily affects a product’s performance, and it’s not possible to accurately measure the change in performance from standard size to actual size without component-level data.

Passive building practitioners are acutely aware of all of the above requirements (and more), as they navigate a sea of data to find windows, doors, and skylights that are the right fit for their project. Fortunately, Phius Certified Windows contain all the component-level data necessary to properly model the thermal performance of a window, door or skylight.

Here is where Phius would like to contribute even further – we plan to release an all new, updated version of our Certified Window Database that offers a robust, easily-navigable list of Phius Certified windows. The goal for this database is to offer practitioners these key features:

  • Photo by Max Lapthorne during a tour of the 425 Grand Concourse project

    Photo by Max Lapthorne during a tour of the 425 Grand Concourse project

    A comprehensive list of Phius Certified windows

  • Data critical to energy modeling and building performance for each Phius Certified window
  • Searching, sorting, and filtering the database to find the right Phius Certified window for a job

While we at Phius think we have a good understanding of what window data is important to passive building practitioners, we also want to make sure that what we produce will be as useful as possible to the community. In order to ensure that we create a worthy tool, we humbly ask that you help us help you.

Are you a CPHC, architect, or engineer? Do you regularly source or model windows for projects? We would love to hear from you. Your input will help us ascertain which data practitioners consider most critical in their search for windows, doors, and skylights.
Please join us for a focus group on Jan. 11 hosted by the Phius Product Certification team (Michael Franco and Graham Wright) and help us understand what you need to find the right transparent envelope components for your projects. Please RSVP here via this link. If you have questions or cannot attend the focus group on the date above and would still like to offer input, email Michael Franco (mfranco@phius.org).

Why Your Project Should be Phius Certified

Why should I certify my project?

That is one of the most common questions we get asked by project teams and their clients. It’s a valid question that can be answered in a number of ways. And while we could go on and on about the advantages of Phius certification, we thought it would be helpful to put together a concise guide to help answer this question. 

As a Klingenblog reader, you may already be familiar with the topics discussed below, but we invite you to use this as a tool should anyone ask you why they should get their project Phius certified. 

Why Certify?

When properly harnessed, passive house principles help create buildings that are efficient, resilient, healthy, durable and comfortable. But if your project is not Phius certified, you have no assurance that it meets any of those criteria.

Simply “incorporating passive house principles” is not enough. Phius certification is the only way to guarantee the quality and performance of a passive house project — like insurance on your investment. Think of certification as a risk management tool. 

That is the Phius Difference.

How does the Phius Certification process guarantee results and benefit project teams and clients? We’re glad you asked.

  1. Park Ave GreenIt provides comprehensive design review and consultation throughout the entire building delivery process Our technical staff works with teams during the design phase to optimize energy and cost efficiency, and to identify and solve potential problems early on.
  2. It mandates third-party verification — This ensures the building is designed and constructed to meet the high-performance standards for energy use and that critical systems are commissioned into proper operation. Third-party verification is also typically required by the incentive programs of utilities and governments to insure their investments. It mitigates risk for all stakeholders in a project.
  3. It introduces risk management — Passive building requires special attention to moisture control and ventilation. Phius Certification staff and third-party QA/QC professionals can identify problem areas at the design stage before they become real-world problems.
  4. It builds and shares knowledge — As more scenarios, project types and solutions pass through the certification process, Phius pays it forward to future project teams through direct feedback, building the public Certified Project Database and ongoing updates to the Guidebook.

So, what is the certification process like?

The Phius Project Certification process has two main components: design review and final construction review. The design review is an iterative feedback process, often exchanging detailed feedback back and forth with the submitter three times before design certification is awarded.

Phius’ feedback isn’t just a yes/no response. We want your projects to be successful and therefore offer insight when red flags arise and are as committed to taking your project to the finish line as you are.

To learn more about submitting a project for certification, visit our Project Certification web page or email certification@phius.org.