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Interesting Elements: A Modeling View on Net Zero Homes

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.

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How to Implement an Efficient Lighting Strategy in a Multifamily Passive House

Walking the aisle of your favorite home improvement store, you’ll notice the wide array of options for very efficient light fixtures. Don’t be fooled – truly efficient lighting design is achieved through thoughtful layout and proper controls.

Hallway lightingA high performance building warrants an efficient lighting strategy. With so many efficient LED fixtures available on the market, individual fixture efficiency is rarely an issue. However, these fixtures are often placed in high concentrations or at a higher wattage than necessary to adequately illuminate a space. The result is high lighting power density (LPD), which is measured by dividing the total light fixture wattage in a room by the square footage of that room. Even with controls such as occupancy or vacancy sensors, high LPDs are especially energy intensive in frequently occupied common areas, e.g., corridors and lobbies of multifamily buildings, impacting the bottom line efficiency of all buildings.

Projects pursuing Passive House certification are impacted by an optimized lighting scheme more so than a code-built building. As the heating and cooling energy used in a Passive House building decreases due to an excellent thermal envelope, the ratio of lighting energy used increases. Reducing lighting energy use can drastically improve the building’s overall primary energy demand. Read more

Home Energy Magazine – The Real Women of Home Performance

SWA Maureen Mahle

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. Read more