Party Walls

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.

(more…)

Groggy and sleepy-eyed, I swung my feet out of bed this morning. Still waking up, I began the trek to my coffee pot, but was thrown off track when my bare feet stumbled (literally) upon a freezing patch of floor beside the door to my balcony. Suddenly wide-eyed, I ducked into the bathroom to rub my toes against my fuzzy bath mat. Outside, the city seemed to have surrendered itself to a single shade of gray, and though my feet were warming, I could feel the monochromatic January cold pressing its way through the metal window. I put on my architect’s (hard) hat and thought, “these are textbook examples of thermal bridging.” But aside from a chill or a draft here and there what’s the big deal? Well, let me provide a little insight.

Thermal bridging occurs when heat is lost through a less-insulated or more-conductive portion of a building’s exterior. On a frigid winter day, this means heat is lost where insulation is lacking, such as through a metal window frame or the floor slab in my apartment building. Ultimately, thermal bridging results in a less comfortable home that is more expensive to heat and cool.

Another hidden concern is condensation, which can be a consequence of thermal bridging. When warm air comes into contact with a cold spot on the floor or wall, water vapor in the air cools and collects as droplets on the colder surface. This can result in durability problems, as well as poor indoor air quality.

(more…)

Home Energy magazine debuted a new interview series on their blog this month titled “The Real Women of Home Performance,” aimed at showcasing the work of women who make significant contributions to the residential energy industry. The first installment of this recurring series features SWA Senior VP and Director of Sustainable Housing Services, Maureen Mahle.

Below is an excerpt of the Q&A session; the full interview is available on Home Energy magazine’s blog. (more…)