One of the most important drivers in achieving Passive House certification (or achieving any goal!) is getting the project team involved from the start. Becker + Becker, the owner, architect and developer for the creative retrofit of the Pirelli Building, hired SWA’s Passive House, LEED, and Enclosures teams to coordinate during early design. Becker +Becker is invested in rebuilding for resilience, sustainability, and occupant health and comfort and appreciates the necessity of getting goals defined at the outset.
AeroBarrier is touted as the best route to never fail another blower door test. The technology, which involves pressurizing a space with a blower door fan while misting a water-based glue into the air from multiple points throughout the space, is most often being used on new multifamily buildings after drywall is installed. SWA first experimented with the technique on the Cornell Tech high-rise building. Back in March, I reached out to Yudah Schwartz at SuperSeal Insulation, Inc. about a personal project, the gut rehab of a 2,500 SF detached single family home. While renovations aren’t something they normally do, Yudah and his team agreed to try a demo. Here’s what happened.
In a collaborative effort that merged financing and energy use analysis, the New York City Passive House industry finally has performance data. Working together with Bright Power, The Community Preservation Corporation, and NYC Department of Housing Preservation & Development, this analysis is the first of its kind.
Why does this matter?
Energy Use Intensity (EUI) measures energy consumption on a per square foot basis to compare buildings and allows interested parties to gauge one building’s usage to another (or to a group of buildings with a similar use type). The study team compared the actual EUI of six completed Passive House-certified and Passive House-like buildings against recently completed multifamily code-built buildings. Information was gleaned from the EnergyScoreCards database and the Passive House (PH) target. The weather normalized data indicates the Passive House and Passive House-like buildings are performing much better than the comparable code-built group, but are not quite as efficient as the Passive House threshold. Industry leaders have recognized this performance gap – between predictive assumptions that rely on standardized patterns of use and the real-life habits of actual people living in the building. This gap has been a hot topic at the past several New York Passive House conferences. The results from the current analysis provide a starting point now, so the industry can focus on strategies to continue to reduce EUIs.
I recently performed some net zero energy modeling on a single-family home for work. Around the same time, I got to chatting with my neighbor (mindful of social distancing) and when I mentioned net zero, he said, “Is that even possible?” AH! Get the word out. We have the means to offset our home energy use. What follows are the basics to consider when trying to fully offset home energy along with a breakdown of how different upgrades can affect energy use.
There are lots of resources available on how to reduce home energy use. You can look at program requirements and guidelines like the Zero Energy Ready Program or Passive House. Through modeling I will demonstrate how the energy use numbers change and describe what we have seen in real-world examples of net zero homes. Net zero is not new and we’ll be looking at some specific pieces of single family home modeling.
Before we get into this topic, please take a few seconds to consider the following questions:
- Do you plan to work, or have you ever worked, on a Passive House building? (If not, the rest of your answers are probably no.)
- Has your Passive House consultant ever told you that the window U-Value you provided “won’t work in their energy model?”
- Has your Passive House consultant ever told you that your window “doesn’t meet the comfort criteria?”
- Have you ever scratched your head when someone asked you to provide the “Psi-spacer” for your window?
If you answered yes to two or more of these queries, please read on. If not, you’ll still learn some useful information, so why not continue?
If you’re still reading, then you are probably somewhat familiar with a “U-Value” and you may know what “SHGC” means. If not, no worries. This article will explain both, and by the end you’ll be able to talk about these terms with most Passive House nerds.