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Building an Affordable, High-Performance Home

Working for Habitat for Humanity is a life-changing experience. We knew going into the high-performance home build in Randolph, Vermont, that the work was important. Affordable housing is one of the most critical issues in communities all over the world – and Vermont is no exception.

But what we didn’t know, was that we would be most impacted by the people.

Join us as we work with the team of volunteers in Central Vermont, and you’ll witness the true spirit of giving back – building up your own community through hard work, patience, and laughter.

 

 

Affordable Housing in Vermont

To better understand the challenge that low-income families face, it’s important to understand the term “housing wage.” It’s the amount a full-time worker needs to earn to afford a modest apartment – while spending no more than 30% of his or her income on rent and utilities. National Low Income Housing Coalition – nlihc.org

Vermont has a housing wage of $22.40 — ranking the 13th highest in the U.S. But the gap between the average hourly wage renters make, $12.85, and housing wage ranks even higher, at fifth in the country, making affordable housing out of reach for many Vermonters. Vermont Digger – vtdigger.org

 

The High-Performance Habitat Home

The Central Vermont Habitat for Humanity (CVHH) is familiar with high-performance building. They’ve got a passive home under their belts, and considered the same for the build in Randolph.

Architect Neil Husher, Vermont Architects Collaborative, designed the home in Randolph to maximize energy-efficiency, and the focus was on tightly air-sealing the entire building envelope.

“We couldn’t do a passive house here because we didn’t have any sunshine, but we could do high-performance, so that was our target to shoot for.”

– Neil Husher, Architect, Volunteer, Vermont Architects Collaborative

 

“With all of the details, it was a learning curve for me. This is framed differently than I’ve ever framed before, it’s actually balloon framed, even up to the rafters,” said Husher. “We also attached the ledger boards for the decking on the inside of the ICF, so there are no rim joist insulation problems, which you normally have on houses.”


Efficiency Vermont

Vermont is a progressive state in regards to energy efficiency, and much of the growth has to do with Efficiency Vermont.

Founded in 2000 as the nation’s first energy-efficient utility, Efficiency Vermont provides technical and financial support to improve the energy efficiency of homes, businesses, and communities.

“Efficiency Vermont is really keen on helping with the social responsibility of living in Vermont.“

– Jennifer Severidt, Energy Consultant – Residential, Efficiency Vermont 

 

For the folks at Habitat, this meant not only a significant refund for achieving an established list of standards, but also personalized help in the support of a Residential Energy Consultant, Jennifer Severidt. Detailed air sealing and continuous insulation were essential components in this build, and Jennifer was not only on hand to explain and review installation details, she worked right along with the rest of the volunteers to install the building materials herself.


The High-Performance Building Materials

To maximize energy-efficiency, Rockwool COMFORTBATT insulation was used in the interior wall cavities, and Dow Styrofoam Blue Board continuous insulation was used on top of the sheathing, to limit thermal bridging through the studs.

“But when we started to look at putting insulation on the exterior walls,” said Severidt, “We thought – What are we going to do about the windows?”

They chose ThermalBuck, which extended the mounting point to create a flush plane with the Blue Board, and insulated the rough openings, to limit thermal bridging in the building envelope.

“ThermalBuck takes care of that problem, of how to create a thermal break at the window, and still have things line up.“

– Jennifer Severidt, Energy Consultant – Residential, Efficiency Vermont

ThermalBuck, the high-performance window buck, is made up of an extremely dense EPS, insulating 4 -times greater than wood window bucks. Coated with a waterproof resin and installed with DAP Dynaflex 800 Sealant and nails, it makes for a complete air and water barrier at the rough openings.

 


The Right Fit for the Build

The team of volunteers in Vermont is led by Project Lead Anne Walker, a former engineer with extensive knowledge of architecture and building.

Crew leaders Glen Seifert and Ken Stevens provided the ideal balance of work skills and people skills, keeping the crew moving along and enjoying the process.

The skill level for the majority of Habitat volunteers is best described as “do-it-yourselfers,” the materials used need to have simple installation methods, easily replicated by a revolving door of people. Not an easy task.

“With wood bucks, you need to have each piece at the right depth. It’s a lot fussier. ThermalBuck is much more precise, and much more forgiving.“

– Anne Walker, Project Lead, Volunteer, Central Vermont Habitat for Humanity 

 

ThermalBuck was an ideal fit, its unique “L” shape makes installing it at the right depth simple.

“ThermalBuck turned out to be a much easier approach to seal our windows, and gave us the added benefit of the thermal break,” said Anne. “With plywood, you’re creating a thermal conduit. But with ThermalBuck, it’s rigid, it’s structural, it’s much easier and faster than having to go around and manually build out the plywood bucking to get these windows aligned with our foam. It was really the perfect product.”


Just last year, The Washington Post reported statistics issued by Freddie Mac, which revealed that between 2010 and 2016, the number of apartments considered affordable for very low-income families across the United States decreased by more than 60 percent. To learn more about planning this high-performance home and the work of Habitat for Humanity, click here.  

Energy Efficiency is a Necessity for Habitat

Habitat for Humanity’s vision is simple:  A world where everyone has a decent place to live. It’s achieving it that’s the complex part. The team at the Central Vermont Habitat for Humanity (CVHFH) is working hard towards that goal, and an even loftier one – building one of the highest performing Habitat for Humanity homes to date, in Randolph, VT.

 

Energy Efficiency: an Essential Need

Building to higher energy-efficient standards is an important consideration for any building project. But the impact on personal health and well-being can be even more significant when making ends meet is a struggle.

“The fluctuating price of energy goes beyond what our families can afford”, says Bruce Landry, Affiliate Building Chair, Volunteer and Weatherization Technician, CVHFH. “The families we partner with start out with very tight budgets and every dollar counts. An energy-efficient home gives stability in heating costs and utility payments.”

“An energy-efficient home gives stability in heating costs and utility payments.”

– Bruce Landry, Affiliate Building Chair, Central VT Habitat for Humanity

 

Not Their First High Performance Rodeo

The home build in Randolph was designed by architect Neil Husher, of Vermont Architects Collaborative. Neil brought three original designs to the table for consideration, which he modified to suit this specific plot of land, and fine-tuned the energy-efficient features for maximum impact.

Although the CVHFH chapter had completed a passive home build in the past, it wasn’t an option for the Randolph home. For instance, there wasn’t enough southern exposure to provide sufficient solar gain. Differences in the wall construction also make this design a bit simpler – building to passive is more detailed, and takes more time. It wasn’t that the volunteer building crew couldn’t handle the technical details and complexity of a passive house, it just wasn’t the right fit for this project. 

 

The High Performance Building Components

The two-story house features 2′ x 8′ wall construction, and an impressive list of high performance building materials including: Rockwool Safe ‘n Sound batt insulation,  Partel VeraPlus smart membrane, Advantech sheathing, 2.0″ Dow Blue Board Styrofoam XPS insulation, Typar WRB, ThermalBuck high performance window bucks, Pella 350 Series windows, Stego Wrap Vapor Barrier, and an Amvic ICF Foundation.

2.5″ ThermalBuck was selected to extend the mounting point for the windows and doors, insulate the rough openings, and prevent moisture at the rough openings – traditionally a difficult detail of any building envelope. ThermalBuck helps simplify the challenge of mounting the windows with the exterior insulation, and integrating the WRB.

8-1-18-window-detail

 

“ThermalBuck makes it easier to do the high performance seals.”

– Anne Walker, Project Manager, Central VT Habitat for Humanity

Employees of BRINC Building Products, Inc., manufacturer of ThermalBuck, will be volunteering to help the CVHFH chapter with their ThermalBuck installation in September, 2018. Keep informed on the next steps of this high performance home by following ThermalBuck on social media:

 

Energy Efficiency in Vermont: More Accessible than Ever

One of the reasons this build was possible? Because it was in Vermont. Efficiency Vermont, founded in 2000 as the nation’s first energy-efficient utility, provides Vermonters with technical and financial support to improve the energy efficiency of their homes, businesses, and communities.

For Central Vermont Habitat for Humanity, this meant not only a significant refund for achieving an established list of standards, but also personalized help in the support of a consultant, Jennifer Severidt. Jennifer was assigned to the project, and provided not just a few answers, but guidance throughout the entire project, answering specific questions like “What specific heat pump would work best?”

 

“We wouldn’t have been able to attempt this without Efficiency Vermont.”

– Debbie Goodwin, Executive Director, Central Vermont Habitat for Humanity

 

Follow this helpful link to view more information about how to work with Efficiency Vermont to receive energy consultation and eligibility for certification, rebates, and third-party testing at efficiencyvermont.com.

 

Habitat for Humanity

Habitat’s mission Is based on the premise that affordable housing plays an integral role in building abundant, strong, and stable communities. Habitat for Humanity is one of the most recognizable efforts to support sustainable housing not only in the U.S, but internationally. To learn more about the efforts of Central Vermont Habitat for Humanity, and how to find local chapters in your area, follow these links:


Habitat for Humanity is not a giveaway program. They offer partner families a no-interest mortgage for their home. In addition to a down payment and monthly mortgage payments, the homeowners invest hundreds of hours of their own labor (sweat equity) into building their new home. Families selected are those who need simple, decent housing, but who are unable to get a loan through any conventional means. Read more about how a family can apply and be selected here.

 

ThermalBuck Outperforms Wood Bucks 2:1 – Thermal Transfer Testing

Improving the energy-efficiency of new and existing construction has long been a focus of the building industry. When it comes to insulation, exterior is the choice of many architects and builders, because it eliminates the thermal bridging through the studs.

However, continuous insulation presents its own unique challenges with installing windows and flashing the rough openings. The mounting point is no longer flush with the sheathing, it must be extended out to meet the exterior insulation depth. Rough openings are always a weak spot for potential water infiltration – and extending the mounting point for windows compounds the problem.

Until ThermalBuck hit the market, there really wasn’t a good way to insulate and create a thermal break around the mounting points of windows & doors. The traditional method to bump out windows was to build a wood window buck. Wood does extend the mounting point, but it doesn’t hold up well to moisture, and it has a low insulating value. With an r-value range of 4.4 per inch, ThermalBuck is a better insulator than wood. But how much? We performed some third-party testing to find out.

 

ThermalBuck installation vs. wood buck installation - thermal break           

Thermal Transfer Performance: ThermalBuck  vs. Wood Buck


Using thermal imaging, we recorded the performance of ThermalBuck against a traditional wood buck in a controlled environment. In the two mock-ups below, three temperature sensors were placed on both the ThermalBuck installation (l) and the wood buck installation (r). The temperature condition on the exterior of the structure was -6.67 ºF, and the indoor of the structure 72.76 ºF.  

 

Performance -Thermal Image wood buck vs. ThermalBuck           thermalbuck vs. wood window buck

These photos show two window installations side by side. (l) ThermalBuck (r) traditional wood buck. 

 

54% More Heat Transfer with Wood vs. ThermalBuck

On the exterior of the structure (point A) the wood buck looses 7.88 ºF, or 14.55 ºF total degrees from the outside temperature. ThermalBuck only loses .11 ºF , or 6.78 total degrees from the outside temperature. The wood window buck allows twice as much energy to escape, while the window installation with ThermalBuck is effectively limiting thermal bridging.

thermalbuck vs wood buck thermal transfer testing drawings
thermalbuck insulating value data charts with Rockwool photo vertical

 

ThermalBuck High-Performance window buck creates a significant thermal break at the mounting points of windows & doors. Using ThermalBuck as part of your continuous insulation solution is an effective way to limit the amount of thermal bridging that occurs through your building envelope.

To learn more about thermal bridging, see what the experts have to say at greenbuildingadvisor.com


Editor’s Note: This article was updated in July 2018. The testing results and thermal images were not changed.

Strength Challenge: ThermalBuck vs. 5,500 lb. Ram Truck

 

When we say ThermalBuck is incredibly strong, we mean it. With a compressive strength of 52 psi, we know it can withstand hurricane force winds with minimal permanent compression. Just for fun, we were curious how it would stand up to John’s new Ram Truck. At over 5,500 lbs (plus John, of course) we wanted to see what would happen when we drove it up onto a piece of ThermalBuck.

To create a simulated window sill, he built a contraption that would allow a 3′ piece of ThermalBuck to be nailed to it, to simulate the same action ThermalBuck would perform when attached to a rough opening. John skipped the sealant, and just used five roofing nails, and nailed them evenly through the 1/2″ tongue, into the simulated sill made of treated lumber.

Next, he built a ramp to get the load of the Ram truck up onto the ThermalBuck, and drove the new truck up on top of it. Not just once, but twice. We heard a loud “snap” on that second trip up onto the ThermalBuck, but it wasn’t the ThermalBuck we heard give, but rather the 2″ x 4″ piece of wood holding it out away from the sill.

ThermalBuck performed, withstanding a large portion of the 5,500 lb. load, with just a slight line of compression along the area where it hit the edge of the window sill. The wood? RIP, 2″ x 4″.


Strong, durable, and lightweight, ThermalBuck withstands wind and shear loads, and remains dimensionally stable.  It helps maintain the integrity of the window installation, which can prevent failure of the window assembly.