Talking Passive House with our very own Gabriela Malone

Interviewed by Russell Chapman

RC: Tell us your story Gabriela. What’s your background and what skills do you rely on most each day as an architectural consultant at Sierra Pacific Windows?

GM: My background is in industrial design and then on to working in high-end kitchen and bath design. My training in interiors, paired with my experience in industrial design, helps me guide my clients in choosing the best materials for their individual projects. I can help them achieve the aesthetic they want all the while ensuring the most durable and high-performance products are used. It always comes down to the right materials and construction paired to the proper application. I’ve been an architectural consultant with Sierra Pacific Windows for almost 4 years now and love working with design professionals.

RC: That’s great Gaby, thank you. What a cool pathway into the fenestration business. I understand you recently took courses to become more familiar with the Passive House program, Passive House Institute United States to be exact. Can you tell us what led you toward learning so much about this high-performance building standard?

GM: I am passionate about architecture and design. My personal philosophy is to consistently educate myself in order to provide window and door technical support that will help design and construction professionals execute projects more efficiently. We had the good fortune of working with April Hughes of HPZS, an award-winning architecture firm in Chicago, who was planning to do a Passive House level gut-rehab. That sparked a lot of research to verify the windows and doors that were being used would meet the performance requirements for the project. This led to a desire to keep learning and become an expert on the subject. With so many high-performance building standards to choose from, it can be difficult to navigate and understand all the options. Most have similar metrics and goals. They may include point-based systems, credit categories, water efficiency standards, energy consumption standards, and more.

We’re seeing an increased demand for energy efficient windows and doors to meet the needs of net-zero, passive house, and other high-performance projects. There’s a whole sub-community of professionals in the realm of sustainable building that are always trying to build a better structure. PHIUS is interesting because it’s comprised of a set of design principles used to attain a quantifiable and rigorous level of energy efficiency. At its core the idea is to ensure the project uses less than 4.75 w/m2-k. This is achieved through super insulation, air tightness and reduced thermal bridging.

RC: Wow, I didn’t realize there was such a groundswell around the Country adopting this standard. Seems like Passive House is poised for growth in the coming years, especially with all the home repair and improvement we’ve witnessed recently. On many of the passive house projects I’ve seen the windows often are imported from Europe and swing inward. Are there products available domestically that might operate more like the windows I’m used to that can help me meet the standard?

GM: While the Passive House standard does not use NFRC Values, important numbers from the manufacturer include:

U-value, Glazing, Frame, SHGC, Visual Transmittance, and Air Leakage

These values will help determine the overall conductivity of each element which in turn will help determine the overall installed u-value. Working with a high-end window manufacturer such as Sierra Pacific Windows, you have access to an entire team dedicated to the architectural community. The windows are constructed in a way that uses sustainable materials like wood, warm edge spacers as well as the ability to utilize different types of low-e glass. The fact that we use warm edge spacers instead of aluminum or steel spacers adds to the window’s insulating factor. Sierra Pacific Windows goes above and beyond.

RC: Is it possible to use a double hung window and meet Passive House standards? In many parts of the Country historic requirements often outweigh energy codes. What other considerations should I be planning for?

GM: Anything is possible but keep in mind that the style of the window greatly affects performance. Sliding and double /single hung windows tend to be at a disadvantage to hinged products due to the difficulty of making them air tight. While using these windows in a passive house might be considered a faux pas, it still might be possible and in particular if there are only a couple units in the project. Generally speaking, having a hinged product allows for double gasketing which reduces air infiltration greatly. In some cases, the look of hung products can be replicated through mulling or grill bars.

Using an energy modeling program is key in strategically designing the building envelope. The construction of the window unit is as important as the walls or roof. Think of the materials within the window unit as part of the overall strategy to make the interior of the home comfortable. The more conductive the window, the more energy you let in or out, the bigger the impact on the overall performance of the building. Passive house energy modeling software considers each element independently; U-value (conductivity of each element), glazing and frame/sash area, SHGC (of the insulated glass itself, not the whole window unit), and air infiltration ratings.

Other critical aspects of a successful project include proper ventilation and moisture management. This means addressing the climate inside by controlling air, vapor and water infiltration. Building for durability and serviceability down the road are also important.

Planning your project is essential. All of the details, dimensions, and technical data need to be run through your energy model to ensure that your targets in the project are being met and this is best done before you build. Once everything looks good on paper it’s time to build. Verification is a cornerstone of any good green building program and Passive House is no exception. Assembling a team that includes a certified passive house consultant, PHIUS builder, architect, window consultant and/or others who are knowledgeable about the techniques required is the key to the success of your project.

RC: That is great information Gabriela, thank you for your time and expertise today.  If our readers have any questions, your local Sierra Pacific Windows team is here to help.  If we don’t know the answer, we will work tirelessly to find it for you.  Find your local Architectural Consultant here.

We’re happy to assist with any and all projects, Passive House or otherwise, or just to make the connection. 

Photo credits for blog: Photo 1: Whitney Kamman Photography | Centre Sky Architecture Photo 2: Karl Neumann Photography