by Bruce Landry
“Simple, decent and affordable,” that is Habitat for Humanity’s mantra. This has meant different things to different people. In 2016, it means building to the Passive House Standard.
Chris Miksic of Montpelier Construction, a certified PHIUS PH Builder and Consultant and Bruce E. Landry of 5 Star Energy Tech presented the concept of a Passive House at Habitat’s All Affiliate Vermont Conference last fall. Everyone was intrigued by the idea of a cost-effective, low energy use PH home. Our challenge was the affordable part of that statement, tracking the cost on a construction estimate spreadsheet and making the spreadsheet transparent is necessary. The goal is to have a turnkey price of $90 to $95 per square foot.
The Town of East Montpelier, Vermont Housing Conservation Board (VHCB) and Cross-VT Trail Association (CVTA) partnered in the Benton Conservation Project. CVTA acquired 11 acres through a VHCB grant, and East Montpelier contributed $12, 000 for the project. Habitat for Humanity sold the project an acre of the land for $1.00 if an “affordable house” were built on it, as a condition of the grant.
Tolya and Otto Stonorov of Stonorov Workshop created the design concept of a simple but efficiently designed three bedroom, one bath, 1250 square foot home that looks and feels spacious. Tolya is a professor of architecture at Norwich University in Vermont, and corroborated with Irene Facciolo of Thunder Mill Design, also a professor of architecture at Norwich University. They taught a semester course on design and construction documentation, and the students produced a complete set of construction drawings and documentation for our project. It was a win-win for everyone involved.
Habitat uses volunteer labor wherever possible to keep construction costs down. Part of the eligibility requirement with the family partners is an agreement to contribute at least 500 hours of “sweat equity.” They have to volunteer hours to build their home. This house is built on a slab instead of a full foundation, which saved money in excavation, concrete, and insulating costs. Vermont Mutual Insurance Group generously donated $15,000. VHCB also accepted a grant application for another $15,000. Marc Companion at the VHCB and Chris Miksic helped to contact vendors that provide high performing materials and efficient equipment. They were able to get corporate discounts for the Mitsubishi Heat Pump mini-split. Klearwall PH windows, Zehnder Heat Recovery Ventilation system, GE Air Source Heat Pump water heater, and sheetrock and cellulose from Wallboard Inc. were all discounted. The dollars saved were starting to add up. Locally, Allen Lumber in Barre and VT-ICF in Waterbury provided favorable pricing for the framing, roofing, siding and foundation insulation. All of these organizations and businesses helped to keep the Passive House Habitat Build move forward and within budget.
With the construction budget under control, the focus turned to the operating cost of the home and the comfort attributes. Depending on homeowner behavior, the total energy cost for a small PH can be as little as $60-80 per month for electricity! The Passive House comfort principle designs for all interior surface temperatures (walls, ceiling and concrete floor) to maintain a maximum of 7.2 degrees F difference to interior air temperature year-round.
Insulation levels and air tightness levels are modeled to assure a healthful moisture migration profile. PH buildings will last generations with no health and structural issues. A Passive House Building / High Performance House prevents the accumulation of trapped water vapor in building components. Century-old homes in Vermont are still standing because their walls and attics have been open, uninsulated and able to vapor-dry on a seasonal basis. The same vapor drying principles are applied to super insulated and air-tight PH envelopes today, assuring that PH will perform efficiently and stand to provide shelter for 100 years and longer.
Early in the design process, building assemblies are critiqued with energy modeling and building- science principles. For PHIUS PH certification, third-party verification of the build process is required. Heating and ventilation equipment is sized properly to save on wasted energy. Design energy models and building assemblies go through a pre-certification process of feedback and evaluation. One hundred years is a long time. PH homes will serve and shelter many generations of families into the future. The added extra quality in craftsmanship, planning, design and cost for certification and verification is time and money well spent if you are planning on building an extremely well insulated, air-tight, low energy house that will last generations.
So, yes, a Passive House is simple, decent and affordable housing, that can and should be built.
Bruce E Landry founded 5 Star Energy Tech in 2007, is a certified Efficiency Vermont Energy Star, BPI, Zero Energy Now and a VT Home Energy Profile contractor. 5 Star Energy Tech is based in Barre, VT. Bruce@5StarEnergyTech.com.
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