Mindful Designs is happy to have recently completed a home that is Energy Star rated. Final third party verification is underway according to the most recent and stringent Energy Star for Homes V3 guidelines. This is a custom design build home in Haskill Basin featuring double stud walls, air seal, HRV and Geothermal heating amongst other high performance items. This is such a low environmental impact home that even the exterior trim was milled from onsite timbers. Congratulations to the new home owners who will enjoy an ultra energy efficient home for many many years.
Within days after uploading some images to Houzz.com we were contacted by one of their editors to write a story on one of our projects. This is another unsolicited article, and we are happy to share it with you.
The Residential Energy Efficiency Credit as well as the American Taxpayer Relief Act are currently offering tax relief for energy efficient installations in new construction AND remodels. MDI has had success in the past with these types of programs and has been able to assist Clients in getting tax credits and incentives when they have installed qualifying components. As the federal and state government and local utility companies see the benefit of installing energy conserving components they are offering an increasing number of kickbacks to the public. MDI, and our knowledgeable team of subcontractors, have successfully been able to participate in the following programs: Energy Star, Montana Home, Flathead Electric Cooperative incentive and loan program, Geothermal tax credits and Air Source Heat Pump Credits. Feel free to call us to discuss any building projects that you have in mind and we can discuss the potential for them to qualify for these and other incentive programs.
In the last blog we discussed some of the attributes of the double stud wall assembly in a custom home that we are currently building in Haskill Basin. This home incorporates not only above code insulation and sealed framing and drywall techniques for a superior thermal envelope, but this home incorporates a geothermal heat system as well. As this home is on track to be an Energy Star home, on site workmanship is verified by an independent third party verifier utilizing real world performance testing of the home itself.
This double stud wall home incorporates advanced framing techniques of a 24” on center load bearing exterior 2 x 4 wall framed in line with a 2 x 4 non load bearing interior wall. A 12” wall cavity between these studs virtually eliminates thermal bridging of the exterior wall assembly. In addition to the oversize wall cavity being completely filled with blown cellulose, this assembly incorporates numerous intentionally redundant air sealing techniques on the interior and exterior planes of the building.
There are some interesting details involved in the air sealing of this home that are not found on standard homes. On the exterior of the building all sheeting seams are sealed and all Teak seams are sealed as well. All penetrations (outlets, lights, vents, etc.) are sealed with spray foam. After using the modified I building wrap technique and flashing pans (crafted out of advanced flex seal tape) all windows are carefully installed in the center of the opening and all shims are removed after installation. This attention to detail allows for a full bead of spray foam to completely adhere the window and the framing for a superior air seal around all window and door openings.
There are additional air sealing techniques on the interior plane as well. All interior wall penetrations (outlets, lights, vents, etc.) are completely sealed themselves and then sealed to the drywall also. The perimeter of wall and ceiling drywall is completely sealed using mastic and gaskets between drywall and the framing.
Some people will ask, “Just how important is the air sealing component when we have so much insulation in the walls and the attic cavity?” The answer is extremely important! Having a well-insulated building that lacks proper air sealing is much like wearing a sweater on a windy day. The insulation the sweater provides does not help you to stay warm if there is no windbreaker to keep that warm air near your body. And the building community is becoming increasingly aware of this fact.
“Air sealing has resulted in up to a 40% reduction of HVAC energy use in cold climates”
Source: NIST Report “Investigation of the impact of Commercial Building Envelope Airtightness on HVAC Energy Use”, S. J. Emmerich, Tim
McDowell, W. Anis
Another major benefit of reducing the amount of air that moves into the building cavities is due to the fact that moisture from the interior environment travels with this warm air.
“Air Currents…account for 90x more moisture vapor entering a wall cavity than diffusion.”
Source: EEBA conference September 27 2012 by Theresa A. Weston, PhD.
In an unsealed home – this moisture enters the building cavities and often has little insulation to prevent condensation when this moist air cools rapidly. This condensation in building cavities has been proven to lead to mold in the building cavities which leads to lower interior air quality and premature building degradation. Proper air sealing techniques drastically improve this situation and thus lead towards higher levels of interior comfort, better interior air quality, less building maintenance and longer life of the structure.
Not all of the energy savings occur with detailing in the field in the Haskill Basin home however. The design details of the home work towards energy savings as well. There are minimized outlets on the exterior walls. Ceiling penetrations (including can lights) have either been eliminated or completely sealed as well.
Although this double stud wall assembly is field proven and works extremely well – we think it is possible to improve upon this system. Just one way we will do this is by incorporating a vapor permeable 1” of spray foam on the inside of the exterior sheeting.
Another option for a structural system with a superior thermal envelope, minimized thermal bridging, and maximum air sealing is a Structural Insulated Panel (SIPs) frame. Our in-house build crew and team of tradesmen have experience with not only stud framing, but with SIPs building as well. This experience allows us to achieve similar thermal benefits as the double stud wall home, with a smaller wall cavity (resulting in a relatively smaller footprint) and less time erecting the super structure on site, amongst other benefits. Please keep an eye on the blog as we will soon have information pertaining to a SIPs home that we just completed. This SIPs home was both designed and built by our in house team for increased efficiency of the design/budget/build process. The new homeowner have expressed how happy and comfortable they are in their SIPs home as the winter sets in.
More details on SIPs homes coming in an upcoming blog soon!
Written by Paul Peters, originally published by the Independent on September 20, 2007
Dr. Kath Williams will tell you right off the bat, “I’m not a tree-hugger. I never cared about the environment, I’m not an architect or an engineer.”
She just happened to be in the right place at the right time to help birth the most respected green building organization in the world: the U.S. Green Building Council.
To her, at the beginning, it seemed more like she was in the wrong place at the wrong time.
In 1994, when the students at Montana State University in Bozeman wanted to build a first-of-its-kind green building on their campus, no one else in university administration wanted to oversee the project. So Williams, assistant to the university’s vice president, got stuck with it.
Williams grew up on a farm in Ohio where, she says, she washed her hair with rainwater and learned to can food from her grandmother. She came to Bozeman after teaching at Stanford, where she found that urban California was no place for her country roots to sink in.
Her life’s ambition, upon arriving in Montana, was to become the president of a university, and overseeing the building project seemed like a detour.
“‘It’ll be good for you,’” she says MSU president Mike Malone told her.
The building was to be a visionary project, way ahead of its time, and an example of how building should be done in the future. Students wanted to call it the Epicenter Project.
“I took that name to Mike Malone,” Williams says. “He said, ‘Kath, MSU is not the epicenter of anything.’”
But the students demanded it, and they had even voted to tax themselves $25 per semester to pay for the building, so Epicenter Project it was.
The project, Williams says, attracted some of the country’s best architects and developers, who wanted to be a part of the revolutionary building.
As they worked on the Epicenter Project, those architects and developers also founded the U.S. Green Building Council (USGBC). The council’s first meetings were held at Big Sky resort.
The USGBC went on to prominence. It developed an internationally recognized points-based method for certifying green homes known as Leadership in Energy and Environmental Design, or LEED, and spawned the World Green Building Council (WGBC) in 1998.
The Epicenter Project, on the other hand, failed miserably.
Too much space in the building was promised out to too many departments, and the project ballooned and ballooned, from 10,000 square feet to 100,000 square feet, and then it popped. In 1999, MSU president Mike Malone died of a heart attack, and the subsequent administration pulled support for the project.
The architects and developers left Montana and moved on to The University of Texas, Houston, where UT’s School of Nursing ended up building the Epicenter Project.
Williams figured she’d go back into administration, but soon people hoping to develop green buildings of their own began calling on her. They’d all been watching the Epicenter Project, had seen it go down in flames, and wanted to hire her as a consultant, to make sure they avoided the traps that killed her project.
“It was like, ‘Why did you fail?’” she says now, laughing. “‘How can we avoid failing like you did?’”
Williams began serving on the USGBC board, representing education, in 1996. She eventually served as vice chair of USGBC for seven years, became the second U.S. representative on the WGBC in 2004, and was then voted president of that organization. She served in that post for three years until she termed out in February 2007. She continues to serve in various roles with both organizations. Read more
A pair of Flathead Valley homes designed by a trio of young builders could soon begin making changes in the local energy grid
USA – Marty Beale, Jason Pohlman and Dave Radaiti, through their Evolution Homes business, first designed and headed up construction this summer of a straw-bale home in Pleasant Valley near the Lost Prairie skydiving field.
Now, the walls are going up at a second “green” home they designed to be tucked behind a field and in front of a stand of trees at the junction of Twin Bridges and Lodgepole roads northwest of Whitefish. Read more