What’s the “most despised” buzzword in the building industry, according to one survey? Green.

Little wonder, since the word can mean so many different things to different people. Before the U.S. Green Building Council (USGBC) launched the Leadership in Energy and Environmental Design (LEED) rating system in 2000, there was little consensus in this country about what constitutes a “green building.” A decade and a half later, some three billion square feet of construction have been certified under the system, and, according to estimates, LEED has cut annual carbon emissions by nearly ten million tons.

Still, some feel LEED doesn’t go far enough, a conviction that led to the 2006 formation of the Living Building Challenge (LBC), which many hold up as architecture’s most ambitious sustainability standard. If LEED serves the middle of the green bell curve, LBC targets the leading edge, an admittedly small segment of the market. What about the lagging end—the least common denominator of green construction? Even the most generous estimates suggest that only half of all new construction is being certified as “green,” and LEED’s entire volume to date represents only about one percent of the total building stock (275 billion square feet in 2010). To speed up the pace and expand the volume of certification, the construction industry urgently needs a quick, easy, affordable way to go green.

Enter Jerry Yudelson. At the beginning of the year, Yudelson, widely known as an authority on sustainable design, was named president of the Green Building Initiative (GBI). The organization runs Green Globes, an alternative to LEED that came to the U.S. in 2004-2005. In January, he announced that the goal was to address the underserved largest portions of the market with a system that is “better, faster, cheaper” than LEED.

Founded by Ward Hubbell, a former PR executive in the timber industry, Green Globes reportedly was set up as a shelter for wood products that don’t readily comply to LEED, which the American Forest and Paper Association has said “disadvantages our companies,” while “Green Globes is much more wood-friendly.” In recent years, the chemical and plastics industries have jumped on the bandwagon, because the latest versions of LEED discourage the use of certain “chemicals of concern,” specifically those found in products such as polyvinyl chloride (PVC)—the so-called “poison plastic” that the EPA, NIH, Department of Health and Human Services, and the World Health Organization all suggest can cause significant health problems. Greenpeace calls PVC “one of the most toxic substances saturating our planet and its inhabitants,” and it has been banned by various organizations, such as Kaiser Permanente.

While the LBC does prohibit PVC, LEED in fact does not; a single optional credit rewards disclosure of chemical ingredients, and specifiers are left to draw their own conclusions. Nevertheless, vinyl lobbyists take a classic slippery-slope position by treating even modest measures as threats.

Reportedly, over two thirds of GBI’s members and nearly half its board represent the timber, chemicals, and plastics industries—industries seemingly spooked by more rigorous standards for human and ecological health. Evidence shows that they’re not just backing Green Globes—they’re actively trying to undermine LEED, and there’s a lot of dirty money at play. From 2007 to 2013, the annual lobbying budget of the American Chemistry Council (ACC), a GBI member, grew by more than five times, and during that period this single organization invested a total of $62 million in influence-peddling.

Image: ArchDaily.com; Sources: US Green Building Council, International Living Future Institute, Green Building Initiative

It’s working: In 2012, a group of Congressmen, many of whom have received significant political contributions from the chemical industry and the ACC itself, urged the General Services Administration (GSA), which manages much of the federal government’s construction, to drop LEED: “We are deeply concerned that the LEED rating system is becoming a tool to punish chemical companies and plastics makers and spread misinformation.” They claimed that vinyl products “are universally considered the most durable, sustainable, and energy efficient by the construction industry” and that their restriction would “severely harm manufacturing in this country.”

Arguing that LEED (or the LBC, for that matter) seeks to “punish” chemical and plastics makers by discouraging the use of potentially harmful substances is like saying that energy efficiency is intended to punish fossil-fuel companies. Nevertheless, last fall the GSA, whose annual buildings budget can be in the tens of billions, endorsed Green Globes for the first time. Additionally, over the past year or two, multiple states, including Alabama, Georgia, Mississippi, and Ohio, have adopted legislation banning LEED in publicly funded buildings.

Given all of this, I was surprised this week when the USGBC and ACC announced that the two organizations would be working together “to improve LEED”: “USGBC and ACC share the goal of advancing sustainability in the built environment,” USGBC President and CEO Rick Fedrizzi wrote in a press release, adding that both entities “will work together to take advantage of our collective strength and experience.” Time will tell exactly what this means. Will the chemical industry embrace smarter solutions? Will LEED become more accommodating to status-quo chemistry? Or is this just the USGBC’s politically astute way to give the ACC a more formal avenue for discussion, in order to defuse anti-LEED lobbying?

In the meantime, Green Globes continues to try to get more market share, and the GBI remains dominated by the timber and chemical industries. So when Yudelson took over in January, I got excited, since I have known and admired him for years. Could he turn Green Globes around?

Immediately upon joining, he announced that he views GBI’s role as that of a “‘friendly competitor,’ rather than a nemesis” to the USGBC: “I don’t really see us getting engaged in anti-LEED activity as an organization.” Privately, he maintains the same position: “GBI is not a lobbying organization,” he assured a group of my peers and me in July. “We do not coordinate with any groups that might lobby for or against other green building rating systems, nor do we participate in such political discussions.”

Yet, in late January—two weeks after Yudelson’s initial claim that his organization planned to stay above the fray—GBI board member Allen Blakey, a vice president with the Vinyl Institute, testified before the Ohio state legislature in support of a proposed ban on LEED, calling its new material standards a “discriminatory and disparaging treatment of vinyl.” This isn’t “friendly” competition. GBI is a charitable organization whose tax-exempt status is contingent on protecting the public good, not private interests, and at least one of its directors appears to be toeing a very fine line between the two.

Chart from BuildingGreen, LEED vs. Green Globes: The Definitive Analysis (2014)

Since taking his new role, Yudelson’s positions seem to have changed in favor of private interests, as well. Last year, before joining GBI, he told a reporter, “We know that a lot of these substances [in materials] have long-term effects [on health].” Since taking his new post, however, he declares, “I haven’t seen persuasive data on the health outcomes of common building materials.” This April, Yudelson called vinyl “benign in use,” possibly contradicting a 2009 report he co-authored (“Inside Going Green”): “PVC is inexpensive and routinely used, but it presents serious fire smoke hazards. Even before it ignites, it releases deadly gases such as hydrogen chloride….Dioxin, the world’s most potent carcinogen, is released when PVC burns.” Since most buildings don’t catch fire, is the phrase “benign in use” Yudelson’s way of sidestepping the “serious hazards” he once attributed to vinyl? Regardless, the EPA, however, classifies vinyl chloride as a carcinogen and maintains that exposure can occur in everyday uses.

Even if the facts about PVC and other materials weren’t “persuasive,” as Yudelson claimed this year, scientists and sustainability leaders long have subscribed to the precautionary principle, which holds that “when an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically.” Yudelson himself advocated for this approach in an interview last year: “[W]e may be creating long-term unhealthy environments even while we’re doing all of these green upgrades. The overarching principle is that we ought to err on the side of caution.”

Yudelson contends that Green Globes is “basically identical” to LEED. Last year, the Portland Tribune considered the merits of the two systems and concluded, “LEED is a more rigorous, broad-based, credible system that delivers more environmental benefits.” This June, the independent consultancy and publisher BuildingGreen released a 90-page “definitive analysis” and found that, in some cases—but only some—Green Globes can be “faster and cheaper” than LEED, as Yudelson insists. But “better”? No. The report specifically calls attention to Green Globes’ weaknesses around the health impact of materials.

In late May, a handful of green building experts and I met with Yudelson to discuss his plans for GBI. We specifically asked him about the board’s composition, anti-LEED lobbying, the health impact of materials, and other important subjects. While the conversation was pleasant, on these topics I found him to be evasive, but he said he would get back to us “within a couple of months.” On June 9, we followed up with a letter, signed by the sustainability leaders of thirty prominent architecture firms, imploring Yudelson to discourage lobbying and campaigning against LEED by stating publicly that GBI does not condone such activities: “We are deeply concerned that a continued campaign against LEED hurts the green building industry as a whole,” we wrote. “The real campaign should be one where all viable green building systems fight shoulder to shoulder to beat back the negative impacts of the built environment.”

Later that month, on June 25, Yudelson sent an email blast to hundreds of industry insiders, criticizing the BuildingGreen report: “Grow[ing] the overall green building market…should be our mutual goal, not engaging in attacks on the merits of one rating tool vs. another.”  On July 12, Yudelson finally replied to our letter from June 9: “I don’t think it’s my role or GBI’s to rise to the defense of a competitive product.” He also asked why we haven’t discouraged “relentless and unfair” attacks on GBI by other organizations (not knowing that some of us actually have spoken to others about raising the level of debate).

In response to this week’s USGBC/ACC press release, Yudelson emailed the group that met in May: “I hope [this will] cause your group to reassess where GBI is coming from in our preference that materials credits (and choices) be based on sound science and proven risk-assessment methods.” Again, this appears to be quite a different attitude from his past recommendations to embrace the precautionary principle.

Six years ago, in The Green Building Revolution (2008), Yudelson defined a “green building” as “a high-performance property that considers and reduces its impact on the environment and human health” [emphasis added]. The building industry urgently needs new solutions that drive wider adoption of green practices, but no sustainability standard can be considered credible today if it does not reflect the latest thinking about the health impact of materials.

Lance Hosey, FAIA, LEED AP, is Chief Sustainability Officer with the global design leader RTKL. His latest book, The Shape of Green: Aesthetics, Ecology, and Design (2012), has been Amazon’s #1 bestseller for sustainable design. Follow him on Twitter: @lancehosey

Citation: Hosey, Lance. "The Green Building Wars" 17 Sep 2014. ArchDaily. Accessed 22 Oct 2014. <http://www.archdaily.com/?p=549176>

Original post from Hammer & Hand's Field Notes blog
September 4, 2014 by Sam Hagerman

This paper, published as part of the 9th Annual North American Passive House Conference, shares the evolution of Hammer & Hand’s wood-framed Passive House envelopes in the Pacific Northwest. Drawing on six projects built in Portland and Seattle over the past four years, I will examine how each of five wall assemblies approached performance, cost, land-use, and durability. The case studies will also chart Hammer & Hand’s move toward developing details that are more familiar to the building community and easy to assemble, moving from unique to common practice. They include:

1. Courtland Place Passive House – a fun carpenter’s puzzle with minimal budget
2. Glasswood Commercial PH Retrofit – Passive House retrofit of a commercial building
3. Karuna House – a high design, high performance showcase
4. Maple Leaf Passive House and Puget Passive House – move more toward standard practice
5. Pumpkin Ridge Passive House – “Let’s do all cellulose!
   

THE FIVE WALL ASSEMBLIES

1. Courtland Place – a carpenter’s puzzle with minimal budget

Project Priorities: This personal project of Hammer & Hand’s Dan Whitmore focused on achieving Passive House with a small budget, using readily available materials and the strengths of the building team to realize complex carpentry details.

Courtland Place wall assembly:

Wall Structure: This house sits atop an insulated slab-on-grade, with the wall cantilevered out to meet the exterior edge of the perimeter EPS and minimize thermal bridging at the foundation wall intersection. Dan used a wall truss whose interior cord bears the structural load and shear of the building. Like a Larsen truss, the exterior cord carries the façade of the building and establishes the insulation cavity.

Air Barrier: The shear panels (OSB) at the inside face of the wall truss form the whole building air barrier, with panel junctions sealed with tape and sealants. (Note: placing the air barrier in this exposed location left it prone to damage from occupants. Though it saved on construction cost, Dan does not recommend the strategy to others.)

Moisture Management: Bulk water is addressed at the cladding with a true ventilated rain screen and WRB over a highly permeable Homasote exterior sheathing. While diffusion can go in either direction, the wall is mostly vapor open to the exterior.

Insulation: 14” deep, dense-packed fiberglass, completed in one pass.

Adaptability: This wall assembly is easily adapted to meet the specific performance requirements of any given project. Alter the dimension of the gusset spanning one cord to the next to change depth of insulation.

Cost: As this project enjoyed very low costs for skilled labor (Dan’s sweat equity as a personal project) it biased toward labor-intensive solutions over moderate- to high-cost materials in order to meet its budgetary targets. For our typical client, this would not have been an appropriate balance.

Land Use: While this wall is fairly thick, choosing dense packed fiberglass over cellulose helped reduce wall thickness by 2 inches. In the end the wall has a moderate impact on the footprint of the building.


2. Glasswood – Passive House retrofit of commercial building

Project Priorities: As a retrofit of a 100-year-old commercial structure this project, like Courtland Place above, was unique for us. Our goals were to reuse and reinforce the existing structure and achieve Passive House certification on a tight lot (and therefore with minimal added material outboard of the original wall face).

Glasswood wall assembly:

Wall Structure: We added shear panels to the exterior and a secondary interior framed wall for additional insulation. To meet fire code we installed DensGlass exterior gypsum sheathing over the layer of rigid exterior insulation.

Air Barrier: The secondary sheathing layer on the interior face of existing wall, taped at all panel edges, serves as the air barrier.

Moisture Management: Exterior Hardie siding handles bulk water with a ¾” ventilated rainscreen cavity. Per Building Science Corporation recommendations, we used Douglas Fir furring strips in lieu of pressure treated lumber in order to minimize environmental impact and construction cost. The WRB is a combination of the Prosoco R-Guard system at punched openings, integrated into a VaporShield membrane installed over the DensGlass. This wall will mostly dry to the interior, though it is open to the exterior through the thinner layer of EPS and ventilated rain screen cavity. Interior moisture conditions are monitored through the ventilation system to ensure that vapor is not driven into the assembly from interior spaces.

Insulation: 2” of EPS exterior insulation, with 7” of dense packed cellulose in the two wall cavities.

Cost: Because this was part of a full building retrofit that involved bringing an historic building up to commercial code, the added expense of reaching Passive House was nominal.

Land Use: Due to the tight site, the 2” of EPS exterior to the existing wall, and 7” of cellulose inside the wall, made Passive House performance possible without increasing building footprint appreciably.


3. Karuna House – a high design, high performance showcase

Project Priorities: Making a beautiful and complex design perform as a Passive House.

Karuna wall assembly:

Wall Structure: A standard 2×6 stick framed wall is integrated into a larger steel structural skeleton. Due to the structural requirements of the exterior stucco cladding, the engineer required a z-joist detail to transfer the load across the 6 inches of exterior polyiso insulation. This z-joist assembly carries through to areas where the house is clad in cedar, as well.

Air Barrier: Exterior sheathing is coated in Prosoco R-Guard system to create the home’s air barrier.

Moisture Management: Bulk water is handled by a combination of cedar and stucco claddings with rain screen cavities. The WRB is provided by the foil-faced exterior insulation, taped at all seams. The Prosoco system provides a secondary layer of bulk water protection of the structure. Drying capacity is to the interior.

Insulation: 6 inches foil-faced polyiso wraps the building. 5.5 inches of dense packed cellulose forms the thermal layer inside the 2×6 wall cavity.

Cost: This was not a budget driven project, though the Passive House “intervention” had to be cost-effective. In the end, making the home perform as a Passive House cost less than 2% of the project budget.

Land Use:  Footprint of the house was not a concern. That said, wall thickness is just moderate.


4. Maple Leaf and Puget – move more toward standard practice

Project(s) Priorities: To use standard materials and established trade practices in building cost-effective Passive House wall systems.

Maple Leaf wall assembly:

Puget wall assembly:

Wall Structure: For both projects, we used a 2×8 stud wall in order to establish a thicker wall cavity without the additional labor involved with a double-stud wall application.

Air Barrier: Structural sheathing, sealed at panel edges, forms the home’s air barrier. Due to field experience, we moved to Prosoco liquid applied sealant in lieu of tape.

Moisture Management: In both homes’ wall systems we installed fiber cement siding over a 3/4” ventilated rainscreen cavity. A membrane establishes the WRB over the rigid exterior insulation. At the exterior sheathing layer a secondary WRB protects the structure. In Puget Passive House we established this secondary WRB using Prosoco R-Guard. Due to lower exposure and budget constraints, we used ZIP Sheathing with its integrated WRB to establish the secondary WRB at Maple Leaf Passive House. The exterior rigid insulation (paper-faced polyiso) has a vapor open covering, so vapor can move out to the ventilated rainscreen cavity or to the interior of the building.

Insulation: Paper-faced polyiso exterior insulation wraps each building (3” at Puget and 4” at Maple Leaf). 7.25” dense packed fiberglass insulation forms an additional thermal layer inside the stud wall cavity.

Cost: The additional cost of exterior insulation, and the lengthy fasteners therefore needed for the siding assembly, was moderate. Time to build the assembly, and therefore labor cost, closely tracks standard construction.

Land Use: With the higher performing R-value of the exterior polyiso, these assemblies have shaved a few valuable inches off wall thickness and building footprint, an important “win” in their urban settings.


5. Pumpkin Ridge – “Let’s do all cellulose!”

Project Priority: For the wall at Pumpkin Ridge Passive House we set out to do a low-embodied energy insulation package, partly to offset the GWP impact of the EPS required in the foundation (necessary to handle sloped site conditions). We were also committed to keep costs low enough that client utility bill savings could pay for any added mortgage service due to those high performance building costs.

Pumpkin Ridge wall assembly:

Wall Structure: We used standard 2×6 wall framing with a Larsen truss system using I-joists. The outer exterior sheathing layer uses Agepan fiberboard.

Air Barrier: The air barrier was easily established at the sheathing layer with liquid applied membrane at seams.

Moisture Management: Bulk water is managed with exterior cedar cladding over a 3/4” ventilated rainscreen cavity. The WRB is provided by the wax impregnated Agepan sheathing. As a cellulose-based, open diffusion wall, vapor can readily leave the assembly in either direction.

Insulation: With a total of 15” of blown-in cellulose in the 9.5” Larsen truss cavity and the 5.5” interior stud bay, the building boasts a very robust, low-embodied energy thermal envelope.

Cost: The ease of installing the I-joist and Agepan combination (and lower labor cost) mitigated the potential complexity of the Larsen truss application and the material costs of the I-joist and Agepan.

Land Use: Land use was not an issue due to the large site, which allowed for a thick wall.


SUMMARY OF WALL ASSEMBLIES BY APPROACH
Air Barrier

1. Sheet goods with tape: Glasswood, Courtland Place
2. Sheet goods, plywood or OSB with liquid applied membrane at seams: Pumpkin Ridge, Maple Leaf
3. Liquid applied membrane applied as continuous layer: Karuna, Puget

Moisture Management – Bulk

1. Liquid applied membrane applied as continuous layer: Karuna, Puget
2. Liquid applied membrane at punched openings with integrated membrane WRB: Glasswood, Courtland Place
3. Treated sheet good (Agepan) with liquid applied membrane at punched openings: Pumpkin Ridge

Insulation

1. Cellulose cavity fill with exterior foam: Glasswood, Karuna
2. Dense fiberglass with exterior foam: Puget, Maple Leaf
3. Larsen Truss with cellulose: Pumpkin Ridge
4. Wall truss with dense blown fiberglass: Courtland Place

CONCLUSION
In reflecting on our approach to these six projects and five wall assemblies over the past four years, the primary driver of design and construction decisions continues to be client preference and site constraints. If the client prefers a building with the lowest embodied energy possible, then stick-framed, exterior Larsen truss with TJI, Agepan, and blown-in cellulose insulation is a fantastic solution. If, however, the project sits on a compact site and is bumping up against zoning restrictions, then the higher performing, and therefore thinner, exterior insulation options (like polyiso) become a better choice. Additionally, as the industry moves toward monolithic exterior rigid insulation in general, it’s a simple process to just thicken up that exterior layer a bit. Both Maple Leaf Passive House and Puget Passive House are good examples of this kind of approach.