2-17-2014 Behind the Drywall Tour – Pushing the ‘envelope’ with 2×4 frame construction
By Douglas Elbinger, Energy Systems Analyst, GreenLancer.com
Green homes. Sustainable homes. High-Performance homes. These phrases can be found on the job every day …but what do they really mean?
To find this out first hand I attended a “Behind the Drywall” tour sponsored by collaborators, Doug Selby of Meadowlark Builders and Michael Klement, AIA, of Architectural Resource, both in Ann Arbor, Michigan. Periodically, they offer the public (those who are on their mailing list) opportunities to enjoy unique project perspectives: glimpses of the inner workings of ‘deep’ green residential projects, both new and remodel…during construction! Attendees are able to see what makes up the core of a super energy-efficient home using a variety of cutting-edge design and building strategies during construction and you get to see and hear how this all works …before the drywall goes up. Behind the Drywall Tour Pushing the ‘envelope’ with 2×4 frame construction
Michael Klement, and Doug Selby, along with building trade allies personally guide attendees through the home (this is actually a construction site) starting in the basement and moving up through the house explaining in vivid detail the how and why numerous energy conservation strategies work in harmony. The tour was very thorough and took about two hours, not including a Q&A session that could have gone on all day if it wasn’t so cold. Since this was a construction site there was no heat. In the face of extreme cold and snowy winter weather …an astounding number of well-bundled guests took advantage of this opportunity to actually see what is behind the dry wall.
The house on this tour, situated on a mature residential street in Ann Arbor, is being totally rebuilt on the original foundation and engineered to use 88% less energy (Yes. You read that right) for heating and cooling than a conventional house of this size. This home is chock-full of cutting-edge technology; Geothermal and radiant heating, Phase Change Material added on top in insulation, Grid tied solar shingles, and there is no furnace or air conditioner, something I’d like to explain in a future article.
“Also consider Earth tubes – to name just a few,” says Doug Selby, Meadowlark Builders President and co-founder, “This home will be the first residential installation of Earth tubes in Southeast Michigan. We are very excited that this client came to us to incorporate this into the home plan and it was great to be able to show this technology to so many people during the tour,” adds Selby.
The Limits of 2×4 Frame Construction
Pushing the envelope means creating the most thermal resistant and airtight building envelope that you can put on traditional 2×4 frame construction. So ‘behind the drywall’ really shows what the limits are when it comes to airtight sealing and diligent thermal insulation. Also, other important components not to be overlooked is the choice and installation of doors and windows
The importance of building envelope
Whether or not your goal is to approach a ‘net zero’ energy standard, you must start with the most efficient building envelope you can afford. Your heating and cooling system’s basic job is to modify the temperature within your house. If we can make the thermal barrier between inside and outside as formidable as possible, less heat will escape in the winter, less heat will get in the summer, and the system will have to do less work. Less work means smaller equipment and less energy. It is possible—and it has been done— to design a house with an envelope so efficient that the house can be heated all winter with the energy of one 60w light bulb. That wall, however, was actually two walls and was about 18” thick. Not everyone can—or wants to—go that far. We can, however, using SIPS (Structural Insulated Panels) and/or foam insulations, make walls and roofs that go a long way in that direction at a reasonable cost. The importance of air sealing the envelope needs to be emphasized and there are products on the market that address this need. Air currents in a building caused by leaks in windows, doors, and walls can account for up to 40% of heat gain/loss, according to a recent US Department of Energy report.
What it looks like inside the 2×4 frame
To lean more about these products and contractors see;
Behind the Drywal Tour – sign up
Michael R. Klement AIA,
Dow Solar Shingles
Energy Alliance Group
Structural Insulated Panels