Image Credit: Martin Holladay To create a ventilated rainscreen gap between the siding and the fiberboard sheathing at the Freas house, workers install vertical furring strips on top of the Tyvek housewrap.
Image Credit: Martin Holladay Here's a great idea: installing a layer of “false ceiling framing” to accommodate wiring and ductwork. At the Freas house, the builders installed a layer of OSB on the underside of the open-web ceiling trusses to establish an air barrier at the ceiling. The OSB seams were carefully sealed with Siga tape from Switzerland. Then a suspended ceiling was installed — 2x6 framing hanging on small Simpson clips — so that electricians and HVAC contractors don't disturb the air barrier.
Image Credit: Martin Holladay The ventilation system at the Freas house uses Zehnder ComfoAire ductwork — long lengths of 3-inch-diameter flexible ductwork made out of high-density polyethylene (HDPE). Each ventilation register gets a dedicated length of home-run ductwork. The duct plenum and HRV have not yet been installed.
Image Credit: Martin Holladay Because Zehnder ComfoAire ductwork comes in long rolls, couplings are rarely necessary; this coupling is carefully sealed with Siga tape.
Image Credit: Martin Holladay The R-55 walls at the Freas house are insulated with blown-in fiberglass.
Image Credit: Martin Holladay This triple-glazed entry door at the Freas house, like the home's windows, was manufactured in Germany by Pazen Fenster. (The U.S. distributor for Pazen Enersign windows is Quantum Builders of Berkeley, Calif.) The door is extra thick and equipped with triple weatherstripping and sturdy hardware with multiple latching points.
Image Credit: Martin Holladay At a panelized wall production facility at the Satsop Business Park, The Artisans Group is putting together thick wall sections for their next Passivhaus project — complete with blown-in fiberglass insulation.
Image Credit: Martin Holladay The double-stud walls being assembled at The Artisans Group's indoor production facility mate a 2x10 wall with a 2x6 wall. The total wall thickness is 17 inches.
Image Credit: Martin Holladay The Artisans Group is building panelized walls at the Satsop Business Park — the new name of the Satsop nuclear power plant. The power plant was under construction from 1977 until 1983, when cost overruns and protests by antinuclear activists finally forced the project to be abandoned, even though construction was already about 80% complete. This cooling tower is right outside the loading door of the wall-panelization workshop.
Image Credit: Martin Holladay Albert Rooks of Small Planet Workshop is now importing and distributing Agepan fiberboard, a vapor-permeable sheathing manufactured by Glunz AG in Meppen, Germany. The fiberboard panels have a thermal resistance that is greater than OSB but less than polystyrene foam.
Image Credit: Martin Holladay
This blog, a report on my three-day visit to Passivhaus construction sites and the Passive House Northwest conference in Washington state, picks up where last week’s blog left off.
After leaving the North residence job site, we drove to the Freas house, another construction site in Olympia. The steep site has a dramatic view of Budd Inlet, an arm of Puget Sound, to the west. (Author’s postscript: On August 15, 2013, the New York Times published an article on the Freas house: “The Passive House: Sealed for Freshness.”)
A modern house with a great view
A design/build company from Olympia, The Artisans Group, is building a single-family Passivhaus on the site. Designed by architect Tessa Smith, the house conforms to a severely modern aesthetic: it’s a flat-roofed rectangle.
Smith is proud to report that (with the possible exception of some gaskets here and there) it’s a no-foam house. The floors, walls, and ceiling are all insulated with blown-in fiberglass. After their insulation contractor had trouble achieving required densities while insulating sheathed walls at the North residence, Smith resolved to change their approach. “We’re not blowing any cavities blind anymore,” she said. “We’re blowing through netting.”
Here’s a summary of the Freas house specs:
- Area: 1,350 s.f. (“treated floor area” = 1,137 s.f.)
- Foundation: unconditioned uninsulated crawl space
- Wall framing: Double 2×4 walls
- Air barrier: OSB with taped seams on interior side of insulation
- Wall sheathing: Vapor-permeable fiberboard
- Floor insulation: 24 in. blown-in fiberglass (R-91)
- Wall insulation: 14. in. blown-in fiberglass (R-55)
- Ceiling insulation: 24 in. blown-in fiberglass (R-91)
- Windows: Triple-glazed Pazen EnerSign; SHGC = 0.54 (glazing only)
- Mechanical ventilation: Zehnder HRV
- Domestic hot water: Gas-fired Navien instantaneous heater
- Design heat load: 7,000 BTU/H
- Space heat: hydronic radiator circulating water from domestic water heater
- Air leakage rate: 0.49 ach50
To learn more about this house and the other sites mentioned in this blog, be sure to click on the photos and read the captions.
Recycling an unwanted nuclear power plant
In the late 1970s, the state of Washington embarked on an ambitious and financially disastrous plan to build a string of nuclear power plants, in spite of the fact that the region is blessed with abundant and cheap hydropower. The agency in charge of building the plants, the Washington Public Power Supply System, had an unfortunate acronym: WPPSS. Almost immediately, the acronym began being pronounced “Whoops.”
Whoops indeed. A variety of factors — huge cost overruns, the Three Mile Island disaster of 1979, and mounting opposition from antinuclear activists — finally [no-glossary]led[/no-glossary] to the abandonment of the ill-fated WPPSS project. As the financial house of cards underpinning the project began collapsing, WPPSS defaulted on $2.25 billion of municipal bonds — the largest municipal bond default in U.S. history.
Construction at one of the WPPSS reactors, the Satsop Nuclear Power Plant in Satsop, Wash., began in 1977. When construction was finally halted in 1983, the plant was 80% complete. Hundreds of millions of dollars were wasted on the facility, which never went on line.
In 1995, someone decided that the unused buildings — many of which have 5-foot-thick walls made of reinforced concrete — should be put to use. Now known as the Satsop Business Park, the facility rents space to start-up businesses.
Workers from The Artisans Group are now building double-stud Passivhaus walls in the one of the Satsop reactor buildings. (There are several advantages to building wall panels indoors, including the avoidance of rain — a common occurrence in the Pacific Northwest.) Since the reactor was never started up, there are (fortunately) no radiation worries at the plant. Considering the recent news from the Fukushima Daiichi plant in Japan, the Satsop tale reads like a swords-into-plowshares fable.
The Passive House Northwest conference
About 200 people gathered on March 18, 2011 for the Passive House Northwest conference on the campus of Evergreen State College in Olympia. Several manufacturers and distributors were marketing their wares at the small trade show, including Albert Rooks of Small Planet Workshop. Rooks was displaying a variety of Siga air-barrier tapes from Switzerland and samples of Agepan fiberboard sheathing from Germany. (Agepan sheathing is thicker and stiffer than the fiberboard sheathing usually sold in the U.S.)
After I delivered the conference’s keynote address — my topic was “Passivhaus Requirements: Logical or Arbitrary?” — we were treated to a full day of presentations by top-notch energy experts, designers, and builders.
Here are some notable quotes from some of the presenters at the conference:
- Michael Aoki-Kramer, RDH Building Sciences: “It costs 3 to 15 times more to fix it later than to do it right the first time.”
- Dylan Lamar, Green Hammer: “PHPP is accurate only for a superinsulated airtight building.”
- Jan Fillinger, EcoBuilding Collaborative of Oregon: “It took us a month to do the PHPP data entry and meet the standard. At first, we didn’t understand the importance of a low surface-to-volume ratio.”
- Tessa Smith, The Artisans Group: “We joke that PHPP is so German and insane, but it is the world’s best energy model.”
My favorite event at the conference was the “Point Sixpack” awards: the annual presentation of a sixpack of beer to each builder who has achieved blower-door results of 0.6 ach50 or better. This year’s recipients included Alex Boetzel of Green Hammer in Portland; Ted Ethan and Mitzi Kugler of West Linn, Oregon; Joe Giampietro, architect of the Mini-B; Dan Whitmore of Black Bird Construction in Seattle; Jan Fillinger (Studio-E Architecture) and Win Swafford (EcoBuilding Collaborative) of Oregon; Glenn Haupt of Bend, Oregon; Milos Jovanovic of Root Design Build in Portland; and Tessa Smith and Randy Foster of The Artisans Group.
Hearty congratulations to all of the Point Sixpack recipients!
The builders and architects I met in Washington state are smart, energy-savvy, and eager to build superinsulated houses. Their regional organization, Passive House Northwest, is unique: no other regional Passivhaus group is as well organized and well funded, and no comparable regional Passivhaus conferences exist in other areas of the country. Their group can serve as a model for other builders and designers interested in superinsulation.
More important, everyone I met was friendly and had a sense of humor, and the locally brewed beer I sampled was hoppy and refreshing — all in all, an excellent visit.
Last week’s blog: “Visiting Passivhaus Job Sites in Washington State.”