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However, because using some traditiona l techniques could hinder certifi cation, builders need to be aware of certain certifi ca- tion requirements. For example, PHIUS has banned the use of certain spray polyurethane foam insulation for its potential for contributing to global warming. " W h i le t he s t a nda rd doesn't necessa r i ly d ic t at e m at er ia l choices, PHIUS is doing a good job on educating, through their professional accreditations, what materials are better than others for a ir qua lity," says Bra ndon Weiss, Founder of Evolutiona r y Home Builders, Graduate Master Builder, PHIUS Certifi ed Builder, Ma ster Cer tif ied Green Professiona l, LEED A P. "Some t y pes of insulations have f la me reta rda nt in them, a nd others don't. DiŒ erent types of fl ooring have diŒ erent levels of formaldehyde and things in them. We take a holistic approach and look at everything." Planning the Project Modeling for airfl ow, energy e® ciency and moisture prevention prior to construction a re keys to PHIUS+ cer tifi cation. W UFI Passive 3.0 software enables designers to assess whether they'll meet energ y e® ciency targets required for certifi cation before construction starts. The newest version of the software includes climate-specifi c modeling, increasing its accuracy and reliability for builders in diŒ erent areas of the United States, who previously relied on models based on European data. More accurate modeling is important for both certifi cation and real-world performance. "A signifi cant amount of energ y is dealt with by conductivity, conducting energ y across our building envelope, so we use a lot more insulation in some regions," says Da n W hitmore, CPHC, PHIUS Certifi ed Builder, Project Supervisor at Hammer and Hand. "The fact that the building code in Tennessee is very similar to the building code in Minnesota doesn't really make a lot of sense from an energetic perspective." Why Go Passive? The cost of passive house construction is often 5–10 percent higher than traditional builds, but reduced energy costs over the long term more than oŒ set higher initial expenses. Passive building can reduce total energy consumption by 60–80 percent and heating and cooling costs by 80–90 percent. As such, this technique is better suited for those who intend to live in a home for a signifi cant amount of time. According to Weiss, 90 percent of building fa ilures involve moisture or water vapor of some sort. By designing the structure to reduce moisture entering the home and improving the structure's d r y i ng potentia ls, bu i lders ca n create more du rable, longer- lasting homes. The Future of Building? Attitudes toward passive house construction have historically tracked with energy prices, and as energy becomes more precious, industry leaders are already beginning to adopt some principles long embraced by passive house builders. "A s we look at bui lding codes… [a nd] the administration of energy codes, they're marching in the direction of what a passive house is delivering right now," W hitmore says. "It 's not rocket science. … It's taking best practice to its logical conclusion for our current buildings. ■ The Myth of Uniformity PERHAPS THE MOST COMMON assumption regarding passive house building is that Passive House Institute United States (PHIUS) standards dictate home appearance. Many passive homes have a distinctly modern aesthetic, but buildings of any size and style can earn PHIUS certifi cation, so long as they meet the organization's performance st andards. "[The] misconception is that there's a single aesthetic associated with [passive building]," says Michael Knezovich, Media Director of PHIUS. "Early examples were all sleek, European and, some thought, too austere. Because of the surface area to volume ratio, it's slightly easier to do larger building." Builders and designers who want to alter the perception of passive house architecture can do so by incorporating passive building techniques into more traditionally styled structures. "The creativity of the design and build team is going to set that tone, along with the client's taste and the type of home they're looking for," says Brandon Weiss, Founder of Evolutionary Home Builders, Graduate Master Builder, PHIUS Certifi ed Builder, Master Certifi ed Green Professional, LEED AP. "Any architectural style can work." "Passive house is the moniker for it, and house doesn't only refer to residences. Passive house building is a nameplate for the methodology for low energy buildings, [which] can be homes, o ces, schools, and churches." — DAN WHITMORE, CPHC, PHIUS CERTIFIED BUILDER, PROJECT SUPERVISOR AT HAMMER AND HAND BOSTON.BUILDERARCHITECT.COM Builder+Architect Greater Boston |

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