Passive House 3 - Sustainable Design Article 5 - JB Hammer Designs

Passive House 3

Reprinted from Examiner.com

Some other Pacific Northwest building professionals, who are crashing the gates of affordable sustainable house plan design, are Larry and Blake Bilyeu, of Bilyeu Homes, Inc. in Salem. They have built several other sustainable homes before they completed their first Passive House (PH). They built it for owners Stuart Rue and Sarah Evans. After an initial learning curve which included PH consultant training for Blake, the project was completed in 9 months. Blake Bilyeu found it "moderately" more difficult than other recent projects, but all in all, it went "very smoothly." Now he knows exactly what to expect and is "very confident" about approaching future PH builds.

Bilyeu claims that he can design a house plan in any genre from modern to historic and conform it to the PH standard. In addition to flexibility in style, flexibility in materials is another characteristic. "The great thing about the (PH) standard is that it can be met with innumerable construction materials and techniques."

Options will only increase as the industry moves towards standardization. According to Bilyeu, "Being on the bleeding edge does have its disadvantages, but there is tremendous collaboration amongst the Certified Passive House Consultants here in the Northwest. As more projects are designed and built, there will certainly be a much larger storehouse of knowledge that will help pave the way for future projects."

Bilyeu believes PH's to be "perfect for the base core of a Net Zero or carbon neutral building - the energy needs are lowered to such a degree that a much smaller photovoltaic array is required." That tactic brings the costs and energy usage way down compared to other sustainable home programs. He likes to use the metaphor that "you have to eat your conservation vegetables before you get your solar cookies." In other words, you lower your energy needs first through proper design and then size and install onsite power generation to reach carbon neutrality.

Stuart Rue, the owner, who has occupied the house since May 2010, has some strong opinions about his PH. In answer to the question; would you build another one, he states: "We would absolutely build to the Passive House standard again, and without reservation recommend it to everybody. Every house should be a Passive House."

Rue goes on to point out that "living in a PH is very much like living in a regular house. The biggest difference is that we almost never need to use the heating/cooling system." The temperature…is also much more even. When I come downstairs in the morning, the floor isn't freezing like it was at our previous house." All of this efficiency is not at the sacrifice of amenities. They have everything in the house that they wanted, attractive, convenient kitchen, attached garage and desired room layout; even a pet door. On top of that, interior and exterior, it is exactly the style they wanted.

Both Bilyeu and Rue make a point of the good air quality. Because of the tightness of these house plans, there is a misconception that indoor air quality suffers. Actually, this house is exceptionally tight. Tightness is measured in air changes per hour (ACH). Northwest Energy Star specs for air changes per hour is a maximum of 7, where this house scored a .2 ! In order to keep the air fresh in such a tight house, an appliance called an Enthalpy Recovery Ventilator (ERV) is used. It allows fresh air into the house and old air out of the house while recovering the energy out of exhausted air. In conventional houses, this air is exchanged through the many leaks in doors, windows, walls, etc. The ERV allows control over the air, which enables control over the indoor air quality, climate and efficiency. Rue calls the indoor air quality "fantastic."

Both owner and builder point out the good economic sense behind building a Passive House plan. Rue claims the costs are reasonable, "only 6% more than if we had not made it a Passive House, and the yearly energy savings represent about a 5.5% annual return on the investment." That means an immediate cost on the Passive aspect of the house of .5%. Once that 6% is totally recouped, it will add up to an annual savings for the life of the home.

One final note worth mentioning; for a passive house plan to be successful, the building envelope must be designed for the climate in which it is to be built. The concept is called Climate-Specific Envelope Design. High performance floors, walls and roofs are so tight, they will trap moisture and cause damage. By the specific placement of a envelope component called a vapor retarder, this problem is avoided.

 

 

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