Q: I understand you are certified Passive House Builder. What are the design principles of passive building?
A: Passive House is the world’s most energy efficient building certification. As such it is critical to minimize heating and cooling loads, minimize lighting and plug loads (LED lighting, super efficient appliances, etc.), and minimize energy used for water heating. Concurrently one should maximize passive strategies such as solar gains, internal heat gains, and take advantage of passive cooling strategies such as opening one’s windows on a cool summers night. This is accomplished through continuous super-insulation, an extremely air-tight building envelope, high quality windows and doors (typically triple pane), and heat recovery ventilation. The Passive House Planning Package (PHPP) computer-modeling software is employed which considers a particular buildings geo-location and orientation to determine the best building form, window locations, and assemblies for the building. The building is then performance tested throughout and after construction by a third party to verify the extremely high performance, low energy Passive house metrics have been met.
Q: What’s living in a passive house look like?
A: A certified Passive House is extremely comfortable. There are no cold drafts, no large, noisy forced air systems, or hot or cold areas of the home. Plenty of natural light and reduced noise pollution further add to the extremely high level of comfort in these homes. Also, people who live in Passive Houses continually remark on the exceptional air quality. Interior air is continuously exchanged for outside air that has been filtered and tempered before entering the building, resulting in air that feels and smells great. Cooking smells don’t linger, allergens and pollutants don’t enter the home, and mold is far less likely to form inside walls. As a result, people with asthma, allergies or chemical sensitivities tend to feel better. One can open windows and doors, do laundry, cook, entertain, or do whatever one does in a typical house, except a Passive House far outperforms typical buildings in terms of comfort, durability, air quality, health, and energy savings.
Q: Are passive houses comfortable in all seasons?
A: Yes. In fact, they are much more comfortable that a conventionally built home no matter what the temperature or season. In fact, the last Passive House Birdsmouth built has only a 7% chance of overheating to more than 77 degrees on the interior during a week of 98 degree days- all without a cooling system!
Q: What are the typical heating and cooling related energy savings compared to typical building?
A: A certified Passive House uses 90% less energy for heating and cooling than a home built to today’s current code standards.
Q: I understand passive buildings are super tight- what about moisture and mold problems?
A: This is a common question, and a good one. By having a dedicated ventilation system, designing assemblies and systems to control relative humidity, and balancing air pressures, the likelihood of any moisture or mold issues in a Passive House is mitigated. Moisture is carried by air, and by controlling where the air comes and goes, one can easily control the moisture that it carries. By having haphazard leaks in a wall and pressure differences- as a typical house may have- one runs the danger of depositing moisture within wall assemblies and leading to mold or durability issues. Intentionally controlling for moisture is central to the Passive House standard, and by employing these proven techniques one can mitigate potential for mold, rot, or building degradation.
Q: Do passive homes all have the same look?
A: Not at all- the Passive House concept can be applied to any architectural style. You can choose the aesthetic that fits your taste. Whether you want craftsman, mid century, English cottage, modern, timberframe, contemporary, etc. it makes no difference, the building can be designed to meet the standard.
Q: Is there a cost premium for this type of building?
A: There does tend to be an up-front cost premium for these buildings. That said, a building built to the Passive House standard typically costs less to live in due to energy bills being low to zero, and over the course of a 30 year mortgage the initial upfront premium is more than recovered. With energy code standards increasing, and more and more high performance building materials being available locally, building to this level is likely to reach cost parity with conventional construction within the next 6-10 years..
Q: Are Passive built homes a good investment?
A: Passive Houses cost less to live in month by month than a typical home. They are higher quality. They are more comfortable, and are designed to last generations. They have less maintenance issues (fewer systems and moving parts), therefore costing less in upkeep. If one uses renewable energy such as solar panels one can have no energy bills. Also, organizations such as Earth Advantage are working with realtors and appraisers to value these homes
for what they are really worth.
Studies have also shown that homes built to green certifications can bring a 5-10% sales premium over similar, non-certified homes.
Q: Do you see an increase in Oregonians embracing sustainable eco-minded home building?
A: We certainly have. I think it is due to a number of factors- a few being the awareness of climate change and wanting to do something about it, greater exposure of high performance buildings in the market via trade magazines, realtors, articles in major publications, and architects, and people simply wanting homes that perform better and are better investments- irrespective of the ‘greenness’ of the building. We more often than not notice our prospective clients ask about performance without being prompted by us.
41% of all the energy used in the United States is used in our buildings. By creating homes that meet the Passive House standard we can make a huge difference in our collective fight against climate change.
Q: What project are you working on that you are most excited about?
A: We have a number of great projects underway from an Earth Advantage Platinum retrofit in the Alameda neighborhood nearing completion, a new Passive House level new home in Hood River, 2 new net zero energy ADU projects starting construction soon, design for a new Passive House certified home and retrofit of an existing duplex for a great, repeat client of ours- among others. It is an exciting time for Birdsmouth all around!
Q: What is your favorite thing about living in Portland?
A: I have always loved this city. I love the proximity to ocean, mountains and outdoors. I love the people. I love the many neighborhoods with their own unique mom and pop shops and lack of big-box style businesses crowding them out. I love the great food and restaurants we have at our fingertips. I love how everything grows here. I love the climate. I love how people live and vote with their values. I could go on and on…
Joshua Salinger is Founder and President of Birdsmouth Construction, a residential and small commercial building and design services company located in Portland OR. Josh graduated from the University of Wisconsin-Madison with a double major in Zoology and Conservation. In 2007 he started Birdsmouth Construction with the goal of designing and building beautiful, high performing homes that transform and improve the built environment. He has received certifications from Earth Advantage’s Sustainable Homes Professional course, and graduated from the Passive House Builders Training program administered by PHIUS. He also sits on the board of Passive House Northwest, a regional trade group dedicated to the promotion of the Passive House concept. He lives in the Mt. Tabor neighborhood of Portland with his wife and 2 children. He enjoys playing guitar, cooking, bemoaning the inefficiency of his house, and making the world’s best cup of coffee.