Air Sealing for High Performance Buildings
Ann Fontaine-Fisher, AIA, LEED AP BD+C, Practice Leader
I recently joined healthcare industry leaders from across the country for a three-day Healthcare Design Forum hosted by Healthcare Design magazine. This was an amazing opportunity to spend three days in a beautiful setting, exchanging ideas with professionals who share the same passion and enthusiasm. The Maine coast venue was ideal. Views of the open ocean from every room helped clear space in our heads for innovative thinking.
The focus of the event was to share our collective experiences and ideas, and engage in problem-solving exercises that would help us tackle some of the more difficult issues we face in our work today.
Upon arrival, each of us was a presented with a list of relevant healthcare topics. The top four issues selected would become the focus of the break-out sessions to follow.
Wednesday afternoon featured a team building exercise: a mini-version of the Amazing Race that was great fun, helped us all get better acquainted, and warmed us up for the work to follow.
Each of the keynote speakers inspired us with a different approach to help fire up the creative thinking juices. Pagan Kennedy, author of Inventology: How WE Dream Up Things that Change the World, discussed the origin of new ideas and inventions. Chris Rockwell, CEO of Lextant, a human experience firm, talked about “empathic care” as it relates to the patient experience. And Martin Kastner, founder and designer of Crucial Detail, shared stories of how he built a business by creating exquisite serving implements that enhance the culinary experience.
In Part II, I’ll get more specific about the breakout sessions, where we really put our minds to work.
--Ann Fontaine-Fisher, AIA, LEED BD+C, Maine Licensed Architect, is a Practice Leader at PDT Architects.
Bob Curtis’s Long-Awaited Talk on the Evolution of PDT Wall Systems
Bob Curtis, PDT’s guru of codes and wall systems, started with the typical commercial wall system of twenty years ago, which resembled the “house system” still used in single family construction, and advanced to today’s rainsceen technology. He paused along the way to discuss the evolution of our choice of wall insulation, from itch-scratchy fiberglass batts installed between steel studs, to supposedly continuous foam plastic insulation boards interrupted by metal zee furring, to our present system of continuous mineral fiber board insulation, penetrated only by fastener or rainscreen support brackets.
Describing the constant battle to keep moisture out of walls, Bob described the old walls as ineffective because of their potential to generate condensation within the wall assembly due to thermal bridging across steel studs. Bob repeated the PDT mantra of favoring simplicity over complexity in wall assemblies by reducing the number of wall assembly components whenever possible. Multiple layers of building materials, insulation materials, and membranes with a variety of permeabilities and water retention characteristics can trap moisture within a wall, which can damage the walls and lead to indoor air quality problems.
Bob contrasted this with the current PDT walls, constructed with a single plane combined air/water/vapor barrier, and a single plane of continuous insulation, that are able to self-regulate their moisture content by drying to the interior or to the exterior as required by changing ambient conditions of temperature and humidity.
Bob reviewed the pros and cons of several of the newer rainscreen “clip and rail” systems designed for use with mineral fiber board insulation and discussed the challenges of maintaining the integrity of a single plane air/water/vapor barrier that is subject to numerous penetrations from fasteners, conduits, and structural members.
PDT is currently designing two major schools to the 2015 edition of the International Energy Conservation Code, above the standards required by the State of Maine. Our office standard building enclosures for all project types typically exceed the current State standard. In the evolving world of building enclosure technology, we always try to anticipate, monitor, and adopt improvements in our choice of systems and materials. This effort makes our buildings tighter, dryer, more comfortable and more energy efficient than ever, with higher R-values and lower utility bills.
–Robert R. Curtis, LEED AP BD+C, Maine Licensed Architect, holds a Maine Code Enforcement Certificate and is an associate of PDT Architects.
Last night I walked over to our community garden plot with my husband and our dog, greeting neighbors (and their dogs) along the way. Within five blocks I can walk to the library, the Quality Shop, Pat’s Meat Market, Baxter Woods, Siano’s restaurant, Roy’s Shoe Repair, the Sewing Shop, Jet Video, and ten other neighborhood amenities. My neighbors walk their kids to school past my house, and from my kitchen I hear games going on in the Deering High School playfields: soccer camp, band practice, lots of cheering.
I live very close to legendary Stevens Avenue in Portland, Maine, the only street in America, we are fond of saying, where you can be born, go to kindergarten through graduate school, work, get married, die, and be buried, all without leaving the street. I think the “born” part refers to the proximity of the old Brighton Medical Center, which no longer does births and isn’t strictly on Stevens anyway, but otherwise it’s true. Stevens Avenue is home to numerous public and private schools, the University of New England, Maine’s only dental school, churches, Maine’s (probably) only Polish restaurant, Aubuchon hardware, coffee shops, and a tattoo parlor. And we all hope to end up under the elegant turf of Evergreen Cemetery.
Courtesy of Friends of Evergreen, friendsofevergreen.org
Until recently, though, my neighborhood, Deering Center, had an unfortunate gap in independent housing for older adults. The houses are modest and vertical. If you can’t do stairs, and you aren’t ready to move into Deering Pavilion, you can’t live in this walking paradise. As my neighbors and I age and retire, a walkable neighborhood promotes not only healthy exercise but the added pleasure of maintaining social bonds. Moving to find simplified one-floor living, cutting the casual ties of neighborhood life, is not only painful, it’s disorienting and isolating.
Reserve your seat at our Bangor half-day forum ‘The Case for Walkability: Health, Economic Development, and Sustainability’ on September 19th. Click here for more information.
Fortunately, construction has begun on the former Sisters of Mercy Mother House, a conversion of the convent into senior housing with the potential for three new buildings of more senior housing to be built behind it. And a smaller apartment building is under construction right next to Roy’s Shoe Repair. As my friends and I get our joints replaced and have a harder time carrying the laundry up two flights, we can look forward to appropriate, convenient housing that makes the legend of Stevens Avenue closer to true. We’ll still be able to live our lives—cradle to grave—and walk to everything.
Marketing Director, PDT Architects
GrowSmart Maine volunteer, Deering Center resident
This blog post originally appeared on growsmartmaine.org.
Architects and Passive House affiliates from Connecticut, Massachusetts, and Maine gathered at the Friends School of Portland for the annual meeting in April. PDT Architects has joined Passivehaus Maine to help expand sustainable building practices and work towards net-zero buildings in New England. Architect Keegan Carmichael attended the meeting.
Since the Friends School has moved to their new building, enrollment has drastically increased. The wall assembly is composed of a 2x6 dense-packed cellulose wood stud with 4” of exterior rigid insulation on strapping and a metal siding. Due to the restriction of passive house air sealing needs, the school does not have a commercial kitchen. The school wanted the most energy efficient building possible, and small tweaks in the building systems allowed for significantly reduced energy bills. Heat pumps run almost 24 hours a day to help regulate the interior temperature. With small amounts of energy used to regulate the temperature, the school avoids peak demand charges and has less stress on the units. Solar panels on the roof pour electricity back into the grid and help with the school’s goal of being net-zero energy.
Due to zoning codes, the Viridescent House currently operates as an office but can be converted back into a house. The office is equipped with a shower and full kitchen, with a south-facing wall that illuminates the open office space and atrium. The building assembly is wood I-joists with dense-packed cellulose fastened onto 2x6 wood studs which sit on a slab on grade on top of 8” of extruded polystyrene. Tidesmart, the client, wanted an extremely efficient building, and with the combination of an airtight super-insulated building and solar panels, the Viridescent House produces twice as much energy as it consumes.
The new school building currently under construction in Freeport will house educational programs and expand the campus. The building envelope is an 8” wood stud with dense-packed cellulose and 4” of mineral wool. Oriented for a passive solar design, the structure will use ductless mini splits for air conditioning. Every classroom has a sink for program flexibility. The new building, with the aid of passive house strategies, is pursuing Maine advanced building certification.
Here is Leland Caron, principal of Caribou Middle School, at AS220 in Providence last week as part of our tour of maker spaces, innovation centers, and project -based learning environments. We spent the better part of two days visiting schools and talking to educators as we begin to design RSU 39's new innovation center.
Jane McCall, assistant superintendent of curriculum and instruction at RSU 39; Leland Caron; Alan Kuniholm and Chelsea Lipham of PDT Architects; and Adam Tilove, head of the Jewish Community Day School of Rhode Island, visited the Rhode Island School of Design, Moses Brown School, Brown University, Wheeler School, AS220, and Berwick Academy, where they visited maker spaces, innovation spaces, and project-based learning environments.
Current designs for the new pre-K-8 school in Caribou call for a maker space in the heart of the school, where students will learn to define problems, collaborate on solutions, choose materials, and gain skills in many different disciplines.
Portland Masonry Company hosted a demonstration at PATHS (Portland Arts and Technical High School) for ACE students GIVE DATE HERE. PDT’s Adam McKinnon, Alyssa Phanitdasack, and Keegan Carmichael attended the bricklaying demonstration by master mason Ed McGarrity. Students learned the fundamentals of masonry as well as a brief history of decorative styles that are prevalent in the Old Port. PATHS offers courses in building trades with a hands-on approach to learning. A list of programs offered at PATHS can be found in the link below.