A Passive PrimerBy Berit Griffin, Marvin Windows
If you’re interested in energy efficiency, Passive building is a phrase you may have heard of, but you may be asking, what exactly does “Passive” mean? To help put some meaning behind the term, we invited Brenda Brunk, a Marvin product planner and our internal Passive building expert, to help shed some light on Passive building.
1. What exactly is Passive building?
Passive building, in its most basic terms, is a process of combining the right building materials to create a highly energy-efficient building. In Passive building, the key is that all of the building components – the foundation, insulation, appliances, windows, etc. – are in sync in a way that uses minimal amounts of energy, or contributes to positive energy gains (i.e., creates energy). Additionally, Passive building takes into consideration things such as the orientation of the home, as this plays a significant role in the amount of solar heat gain or loss through windows, which can contribute to the overall efficiency of the home. When it comes to windows in Passive building, various glazing (glass) types and Low E coatings may be used for windows on certain elevations in the building, and the windows may be sized or shaded to balance the overall solar heat gain or loss throughout the entire building.
2. Why would a homeowner choose to build a Passive House?
If a homeowner desires low energy costs and improved efficiency of their home, they should consider a Passive building. Passive building requirements are very stringent, so I would also remind people that you can still have a very efficient home without having to go completely Passive.
3. Okay. So if I want an energy-efficient home, but am not sure I want to build a completely Passive House, what are some things I should consider?
It really comes down to balance. When building an energy-efficient home of any kind, it is important to take a look at the cost of the components, or building materials, used in the building, along with the cost to occupy. Although the cost of certain materials may be high in specific areas, many times those costs can be offset with the cost of other materials or equipment. For example, an investment in high-quality windows or insulation may mean less cost for heating and cooling equipment and will result in lower long-term energy costs. I would encourage homeowners to review the overall costs and look at the big picture to make the determination that is right for them. It is important to keep in mind that although Passive House uses the most rigorous criteria for energy efficiency, there are many alternatives that are very effective in controlling energy efficiency as well. When considering alternatives, look for those that are backed by science and proven technology; options include ENERGY STAR Most Efficient and DOE Zero Energy Ready.
4. How should I choose trade pros to work with? How do I know they know about energy-efficient/Passive building?
I would recommend seeking trade professionals who have experience in energy-efficient design, and have demonstrated the capability through completed projects. Look for someone in your area who considers energy, efficiency, as well as alternative materials. Most importantly, find a professional that is educated in Passive House and willing to listen to your needs and respond with options to accomplish your goals.
5. What Marvin products should I use in my Passive project?
There are a number of Marvin products to choose from for your Passive building project, as well as an array of low E coatings, glazing types and gas fills to suit many areas in the U.S. Marvin has limitless options and types of windows to select from, so I would recommend looking for the window types with the best air infiltration numbers such as the Ultimate Casement, Simulated Double Hung Hopper or the Direct Glaze rectangular unit. You can then “solar tune” the glass to your climate by choosing a Low E coating to help control solar heat gains. I would encourage visiting with your Marvin representative to help explain and narrow down the options.