Typology: Passive House Proficiency

For over a decade, Julie and Tarek Alkatout have resided comfortably in the “Nordeast” community of Minneapolis, Minnesota. While seeking to remodel and retrofit their abode to better accommodate their family of five, the benefits of “amazing neighbors, houses with character, mature trees, unique restaurants,” as well as convenient proximity to both Minneapolis’ and St. Paul’s bustling downtown districts, gave the family little reason to leave. Initially considering the possibility of a retrofit venture, a different opportunity befell the Nordeast Nest in an unlikely place—the house next door.

Though dilapidated beyond repair and resting uninhabited for an untold number of years, the prospect of exploiting the adjacent home seemed increasingly attractive to the Alkatouts after calculating their options. “Looking at the residual value of that structure, the cost of the retrofit, and the market value of their existing home, it was more advantageous to build new than to retrofit,” explains Tim Eian, founder of architectural firm TE Studio. Eian also was a founding board member of the Passive House Alliance, US, an area of rare expertise in North America, that the couple grew interested in harnessing. “I think they just liked the quality and comfort aspect of it, and they also want to tread lightly in terms of environmental footprint,” Eian surmises, all qualities of which TE Studio is preeminent in begetting.

The standards and prerequisites touted by Passive House aren’t as widely known, though they’re well defined—insulation and building envelope being among the primary focuses. “The basic gist of it is that there’s an air tightness standard that we have to meet and a heating, as well as a total, overall energy consumption limit per square foot of house,” outlines Ryan Stegora, proprietor of RJ Stegora, Inc.and construction contractor on the Nordeast Nest. Also pertinent to Passive House certification is solar heat gain, an obstacle given the unnavigable shading drawn from the neighboring home. Solar hindrances notwithstanding, however, the Nordeast Nest is an exemplary Passive House prizewinner, performing in the top percentile of energy efficiency.

Among the more recent accolades that the project has attracted, the home has earned a “5-Star Plus” energy rating score. And, in addition, it has been noted that, in terms of comfort and energy consumption, the Nordeast Nest “outperforms the previous home by a huge margin.” Much of this enhancement can be attributed to the strict insulation and rigid air tightness, as is characteristic of Passive House efforts, however Eian and Stegora agree that the windows are the home’s most powerfully alluring feature. Imported from Germany, the windows are triple-pane tilt-and-turn units with insulated frames. “It’s hard to describe in words how much better they look and feel, and how comfort is increased through a unit like that,” Eian boasts. The high-gain windows are but one factor in the success of Eian and Stegora’s collaborative pursuits. “Following details with diligence and quality control throughout the entire project were the biggest factors,” says Stegora. “We’re both very dedicated to putting together an extremely well built home. Both of us have a passion for what we do and that shows in our work.”

Taken By Storm

ONE HOME DESTROYED IN THE WAKE OF HURRICANE SANDY SEES REINCARNATION IN THE FORM OF A CERTIFIED PASSIVE HOUSE

By Vincent Caruso

In 2012, our nation was made a disquieting acquaintance with a formidable category 3 storm that would scar the public’s psyche and upend the lives of Americans across 24 states. Among the upwards of 15,000 people who lost their homes in the wake of Hurricane Sandy were clients of Passive House consultant Nina Shah-Giannaris and architect and Passive House consultant Anthony J. Musso—clients who had lost their home to the seize of a fire. Musso’s involvement with the project came at the bidding of Shah-Giannaris, Green Engineering Projects president and owner, who knows the clients personally and was first approached by them with interest in rebuilding as a decidedly energy efficient and sustainable home. It was then that Shah-Giannaris upped the ante and suggested pursuing the Passive House standard, to which the clients responded with eager approval.

Following the inaugural meeting to discuss the clients’ basic family needs, the initial design of theBergman Passive House was produced in the form of a hand sketch drawn out meticulously by Musso on an airplane. This primordial draft laid the foundation for an intricate network of stringently eco-conscious mechanizations, as well as the capacity to expertly leap through ancillary Passive House regulatory hurdles. But these hurdles were anything but insurmountable. Such leaps proved simply to be a matter of “doing the right detailing and choosing the right materials, talking to PHIUS (Passive House Institute US) in terms of what we can do and what we can’t do,” Musso says. The team’s initial plan, for instance—to seal the elevated floor with watertight membrane—was thwarted in favor of an open vapor system to drain in total the moisture from the floor system, thereby producing optimal insulation and vapor seal.

The virtue of team cooperation is one that Musso and Shah-Giannaris are quick to credit with the success of the passive house project, and its merits are demonstrated in far more than just a well-insulated floor. “Also,” adds Musso, “when we were looking at domestic hot water, we were initially going to go with a tankless electric heater,” a popular and reliable enough system, but one that was shyly short of complying with Passive House requirements. The stonewall led the two to commit instead to an electric heat pump system, which is about three times more efficient than the tankless electric heater.

Getting as much out of natural resources was also a priority. “Everything is climate dependent,” philosophizes Shah-Giannaris, this aphorism too serving as a useful general work credo. Musso, illustrating the fruits of this motto, recounts, “we had a very good south exposure, so we were able to position the house to get the optimum solar gain.” Geography also played a central role to the clients early on, expressing a desire to capture as much of their immediate environment as possible. “They are one block from the channels that lead to the Great South Bay,” Musso highlights, and the clients were rightfully interested in enjoying a south view of the water. By adding roof balconies accessible from the master bedroom, the team was able to afford their clients just that. It’s a high degree of luxury, and one that can only be achieved by way of a high degree of efficiency—so much so that the home was projected to exceed code standards by 80%. By project completion, the Bergman Passive House exceeded code by a monumental 91% achieving a HERS score of 9.

Reduce Reuse Rehau

THE POLYMER SOLUTIONS COMPANY USES THE RIGHT WINDOW TO GUIDE THE COUNTRY’S LARGEST PASSIVE BUILDING TOWARD AFFORDABLE SUSTAINABILITY

By Emily Torem

When designing the windows for Portland’s Orchards at Orenco, the country’s largest Passive House multifamily complex, Ray Gilbert, account manager at window and door solutions providers REHAU(along with the company’s fabrication partner, EuroLine Windows) knew he needed something extraordinarily efficient. REACH, the affordable housing non-profit behind this ambitious project, wanted the Orchards to fill the gap in the city’s growing market for affordable housing. A simultaneous goal was to demonstrate that sustainable designs don’t have to be priced prohibitively; rather, energy-saving measures can work in tandem to create affordable living for tenants long-term—not just when they sign their lease.

Gilbert sought a material that would provide superior insulation against both heat and cold. “The typical North American window, a double hung horizontal slider, loses air at a rate of .15-.30 cubic feet per minute,” Gilbert says—a recipe for skyrocketing utility bills. The Orchards also sit adjacent to a Light Rail Line, frequented daily by locals in Suburban Portland, so sound insulation was essential, too.

“Passive House is very concerned about air leakage,” Gilbert adds. Keeping the building’s envelope well insulated and sealed against that leakage is the best line of defense against overuse of HVAC systems as external temperatures fluctuate. With that in mind, Gilbert met with Dylan Lamar of Green Hammer, a Portland-based design/build company that specializes in Passive House, to help inform the decision-making process on windows and doors.

Ankrom Moisan Architects, who spearheaded the project, didn’t want all fiberglass, because it lacked the ability to be welded at all corners of the sash and frame necessary to provide true longevity for tenants as alternating colder and warmer spells caused building components to naturally expand and contract. The perfect solution was found when

Gilbert proposed the GENEO window, which provided the time-tested strength of fiberglass combined with the weather-fighting flexibility of uPVC, which has the benefit of the fully fusion-welded corners on sashes & frames as opposed to mechanically joined corners in pure fiberglass windows (which creates leakage over time).

GENEO features a tilt-turn design, which Gilbert says was difficult to find in North America, but luckily was provided by REHAU fabricator EuroLine Windows in nearby British Columbia—less than 350 miles away from the Orchards project. Tilt-turn, a common window variety in Europe, allows for a full 360-degree seal around the perimeter of the window, preventing ambient air from escaping and requiring HVAC systems to work overtime to keep homes at a comfortable temperature. GENEO can also be triple or quadruple glazed, trapping columns of air between panes to provide extra warmth in the winter and preventing extra heat from entering the interior in the summer.

The placement of GENEO further helped in passively heating and cooling the units at the Orchards. Their placement on Southern-facing facades helps them accumulate heat from the sun during the winter, while overhangs and balconies help provide shade in the summer to protect buildings from excessive direct sun. As for the noise factor, Gilbert explains why GENEO was able to achieve a massive 43-decibel reduction. “GENEO has multiple locking points around the window, [allowing] it to seal 360 degrees around the frame,” he says.

GENEO tilt-turn windows helped the Orchards at Orenco not only adhere to, but exceed the requirements for US Passive House, enabling seamless savings for lower income tenants. “With Passive House, you can achieve up to a 90% reduction in energy bills versus conventional construction,” Gilbert says, citing a case study conducted on Orchards. The Orchards at Orenco is a supporting example of the concept that environmental sustainability goes hand in hand with financial sustainability across a variety of income levels.