A Passive House Design (with a Few Curves Thrown In)

passive house designUnlike many panelized home builders who enclose their home shells using standard XPS and EPS foam core SIPs exclusively, Bensonwood builds many of its own structural, insulated wall and roof panels to realize the visions of its in-house design team and outside architects alike, while reducing waste by eliminating cutouts for doors and windows, which are not recyclable and end up in landfills.

Our walls feature dense-pack cellulose for insulation (a renewable, recycled product), and can be easily upgraded to extreme R-Value and air tightness for Passive House levels of performance. They also incorporate our Open-Built® chases for easy access to wiring and plumbing.

passive house curvesPerhaps best of all, our custom panels can accommodate curved walls and join complex, compound roof pitches to realize the contemporary designs of even the most innovative architects. One such Passive House design, by Jonathan Knowles and Laura Briggs of Briggs Knowles Architecture + Design, is a strategically sited home on a wooded lot in the Hudson River Valley of New York. Passive House is a rapidly emerging standard requiring that buildings use extremely small amounts of energy for heating and cooling.

The striking 3-bedroom, 2.5-bath house re-imagines the often utilitarian designs of the Passive House vernacular with its own unique curvilinear aesthetic, open space plan and multi-level views.

passive house walls panelThe first-floor plan includes a living area with a wood stove and screened porch, a separate kitchen and dining area, 2 bedrooms, 1.5 baths, a mechanical room, and a polished concrete floor. The dining area and one of the bedrooms are built into the curvature of the outer wall design, creating interesting interior spaces and angled wall partitions.

The second-floor plan has a generous, curved master suite complete with a large walk-in closet, sauna, bamboo wood floor, balcony, and dramatic, cantilevered porch. Rounding out the second floor is a large playroom open on one end to the living area below.

Bensonwood delivered and rapidly raised the home shell in the middle of winter, with R-49 roof panels and R-35 wall panels pre-installed with Zola triple-glazed windows. From there, the on-site builder, John Hommel of Ashley Homes, added additional layers of insulation to easily bring the house up to Passive House levels of performance.

Bensonwood Earns FSC Certification

FSC LOGOBensonwood is proud to announce that we have received Chain of Custody certification from the Forest Stewardship Council (FSC). FSC Chain of Custody certification provides customers with independent assurance that a product supports responsible forest management. It can also be used to verify that a product is from post-consumer recycled sources.

We have long sought the most sustainable products and building methods over the past 40 years, but this an important further step in demonstrating our commitment to responsible forestry practises.

The FSC is the global leader in responsible forest management. As a member led organization with economic, social and environmental interests sharing equal authority, FSC represents a consensus voice of forest stewardship, affording forest stakeholders a seat at the table. As a nonprofit, FSC sets high standards that ensure forestry is practiced in an environmentally responsible, socially beneficial, and economically prosperous way.

Landowners and companies that sell forest products seek FSC certification as a way to verify to consumers that their products are sourced from well-managed forests consistent with FSC standards. Thanks in part to the recognition of the FSC in the Leadership in Energy & Environmental Design (LEED) program of the U.S. Green Building Council, there has been a surge in the use of FSC certified wood in green building projects.

Many green homebuilding programs and the nation’s largest DIY retailers, along with many local lumberyards, recognize FSC as the best guarantee of responsible sourcing of wood building products. FSC-certified building products include a wide array of lumber, sheet goods, flooring, millwork, doors, windows, paneling and decking.

For more information on the Forest Stewardship Council visit their website.

Unity Homes’ Air Source Heat Pumps: Pulling Energy Out of Thin Air

By Rheannon DeMond

Bensonwood/ Unity Homes Energy and Sustainability Specialist

ASHP DIAGRAMHeat pump technology has been around for over a century, and even though the technology has advanced, the principles are still the same. There are some who are still critical about Air Source Heat Pump (ASHP) technology, but we at Bensonwood and Unity Homes prefer to use them whenever possible as they’re especially well suited for highly- insulated, airtight homes with very low heating and cooling loads. In fact, our building envelopes are so energy efficient that our smaller, open floor plan homes can often be comfortably heated and cooled with one central unit. Regardless of home size, however, Air Source Heat Pumps are an extraordinarily efficient and feasible option for our homes, and this article will cover why we think this technology is the best all-around choice.

Technology

Unlike combustion-based systems that produce heat at around 80-95% efficiency, ASHPs move heat from one location to another using the energy drive from the refrigeration cycle. This process is very similar to how a household refrigerator works.  The increased energy drive allows a heat pump to produce 100 kWh of heating and cooling energy using only 20-40 kWh of electricity, resulting in efficiencies of 200-350%.

ASHP IMAGEHow much electricity is consumed is dependent on the temperature differential between the outdoor and indoor air. In fact, a common reason people have shied away from using ASHPs in the past is because the efficiencies drop in cold temperatures, making these units not as ideal for cooler climates. However, recent advances in the inverter technology of these systems now allow ASHPs to operate down to -17°F, and produce heat at 100% of its capacity and efficiency down to 0°F.

Energy Usage

ASHP technology is efficient and here is a real life example to put it a little more in perspective:

For a 1,780 SF northern Vermont home that requires around 57.1 million Btus per year to heat:

Heating with #2 fuel oil would cost around $1,600 a year at current rates.

  • Heating with a propane-fired system would cost around $2,000 a year.
  • Heating with wood would be the least expensive option at around $850 per year (but the effectiveness is highly dependent on the user, stove design and kind of wood being burned.)

It should be noted that all of the aforementioned options use combustion, which we know is bad for the environment.

  • Electric resistance heat would cost around $2,500 per year and the impact that would have on the environment would be dependent on the source of electricity.
  • Air Source Heat Pumps can generate the same amount of heat for only $1,090 per year, and they can provide efficient cooling in the summer!

Environmental Impact

If the electricity used to operate an Air Source Heat Pump is generated by a renewable energy source, then the system has little to no impact on the environment. Oil, gas and wood-fired systems create heat using combustion. Combustion creates carbon dioxide, which is harmful to the environment and is a leading cause of unsafe emissions released into the atmosphere every day.

Using the same northern Vermont home as an example, the difference in electrical usage between electric resistance heat and the heat produced from an ASHP is around 9,500 kWh per year. A great way to look at those savings is how it will reduce the impact on the environment, as well as your wallet.

This EPA website allows one to input estimated energy offsets and see how those savings will reduce the impact on the environment. A savings of 9,500 kWhrs is the equivalent to eliminating the CO2 Emissions from 737 gallons of consumed gasoline, or 7,037 pounds of coal burned or 15.5 barrels of oil consumed. And that is just one year. Imagine what the environmental savings would be over 30 years.

Feasibility

Air Source Heat Pumps can be ducted, centrally located or zoned with multiple head units.  The system uses small copper refrigeration lines for connections, which minimizes required mechanical space and makes zoning much simpler. They offer a variety of head units that fit easily in both new and existing construction projects, and with their low operating loads these systems can be easily powered by a small renewable energy source.

Installation Costs and Return on Investment

We’ve already discussed how Air Source Heat Pump systems can save money on annual utility bills, but for something so efficient one would think it has to cost more money than conventional systems, right?  Wrong. These systems are very cost competitive with most other systems, and remember, they provide whole house cooling and heating, so they may even end up being less expensive.

So what is the return on investment on a system that will not cost the consumer any additional money? It is immediate, but on average this system will pay for itself in energy savings in less than six years!

 Cold Climate Operation

The one downfall to these systems is that at around -17°F there is a chance these systems will shut down and stop producing heat, which is what scares some people away. What these people do not understand though is how infrequently the temperature drops below minus 17°F in most of the United States. Even in the coldest climates this is not a common occurrence, so not using a system that is as efficient as this one because of that one fact is not the right approach.

A simple back up source of heat can be installed for use in these rare occurrences. In our homes we use electric resistance for back up heat, because it is inexpensive and can also serve as zone heating. There are also systems available with electric resistance back up heaters that will continue to operate into these low temperatures.

Other Types of Heat Pumps

After heating and cooling, domestic hot water consumes the most household energy, but luckily they also make a heat pump for that. Heat pump water heaters operate at high efficiencies, and have settings to ensure a steady rate of hot water.  When compared to electric resistance, oil and propane powered systems, these units will see a return on investment in less than three years. The only catch is that how efficiently they operate is dependent on the ambient air around the system, so installing a unit in a cold basement would not be ideal, but if you have a continuous source of heat to pull from, these units are a great and affordable solution.

Geothermal or Ground and Water Source Heat Pumps (GSHPs) operate using the same heat pump technology as air source, except they move heat using the consistently warmer temperatures of the earth and ground water.  Because of this they can operate at efficiencies of 300-600%. These systems are very popular in European countries with very strict guidelines for energy usage.

GSHPs are growing more popular in the cold climates of the United States, but they have high upfront installation costs and a small pool of qualified installers. Like most emerging and efficient technologies, it may take some time before these systems are offered at prices that offer an attractive return on investment.

Conclusion

Buildings are responsible for around 40% of the carbon emissions released into the atmosphere every day, and with the fluctuating cost and availability of fossil fuels, and threat of irreversible climate change, another solution is very necessary. With the advancements in heat pump technology and decreasing costs of renewable solar energy, achieving net zero energy consumption is not just feasible, but a great investment as well.

A Classic Barn for a Classic Car Enthusiast

elevation of classic car garageAre you one of those people who owns a classic car and longs for an appropriate place to keep your dream machine? That was the impetus behind one car enthusiast’s desire to physically connect his passion for collectible automobiles to his existing 1930s Delaware residence. The owner, who has an existing garage for his family cars, tools around in a ‘76 Triumph TR6 and hopes to acquire more vintage cars once his new timber frame car barn is completed next month. The result will be an architecturally true barn and connector addition that can drive home, literally, his automotive passion.

The barn and connector were designed by Patrick McDonough, of John Milner Architects, to integrate and reflect the style of the existing main house while adding to the majesty and proportion of the façade.

classic car garage elevationBensonwood was hired by the owner/builder, a repeat client, to fabricate and raise the free-standing timber frame barn shell. The lengthy connector joining the house with the barn will be site-built by Dewson Construction Company, a Delaware-based general contractor and construction management firm.

The car barn, with four bays and an epoxy-painted concrete floor to showcase the vehicles, will be a traditional design, with a single, 28-foot-long glulam girder to achieve a post-free opening to the shed bump at the rear of the building. Roof trusses on either end of the barn will have straight bottom chords, with three arched glulam bottom chords on the trusses in between, defining the vaulted space. The structure includes a central king post with decorative and structural steel reinforcement plate custom fabricated by Bob Taylor of Alstead, NH. A multi-purpose loft with ladder at one end of the structure will add useful square footage to the plan.classic car garage interior rendering

CAD DRAWING vintage auto barnTo integrate the architectural style of the barn with the main house, an eight-sided “lantern” cupola will be stick-built atop the barn by a local company to match the cupola on the main house. In addition to its unifying aesthetic, the copula will allow in natural light to illuminate the timber frame interior and future car collection. Dewson Construction will then finish the barn with a brick exterior to match the main house.

The classic car barn, currently in fabrication at our Blackjack Crossing facilities in Walpole, NH, is slotted for a September 15 raising, with the complete weather-tight shell installed within a week’s time.

Aquatic Dreamhouse Required Fluid Construction Strategies

Pool-Centric Vision Posed Technical Challenges

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Faced with a significant technical challenge, Alfandre Architecture, PC and its construction company, EcoBuilders Inc., teamed up with Bensonwood to fabricate and install the large-span glulam timbers and insulated shell of this spectacular 6,000 SF timbered dream house — all built around a large 2,000 SF indoor pool — for their client, a retired couple in Putnam County, NY.

pool house living areaThe challenges included engineering the long timber spans of the pool room, humidity control and the sensitivity of the rocky build site, to name a few. Here, Bensonwood’s expertise in timber engineering, off-site fabrication of panelized assemblies and rapid on-site installation was instrumental in realizing the ambitious project with minimal disruption to the ecology of the home site.

The house, recessed into the bedrock of its 15-acre site, was designed by architect Rick Alfandre to complement its natural setting, with the pool room both anchoring the design and providing the homeowners with the physical, social and emotional benefits of their daily one-hour swim. To add to the ambiance, the light-drenched, four-bedroom, five-bath home has over 70 triple-glazed windows to draw the surrounding landscape into its interior.

pool in upstate ny dream houseGC and local construction company, EcoBuilders Inc. (owned and operated by Rick Alfandre) completed the foundation and walkout walls, first floor system, infill, window installation, mechanical systems, and finishes.

From this project, Bensonwood went on to contribute the timberframe and roof panels for Alfandre Architecture’s offices across the Hudson River in New Paltz, NY, for which Alfandre is seeking LEED Gold certification.

For more photos, visit our Houzz Page.

Bensonwood Featured in “The New Net Zero” by William Maclay

the new net zeroThe New Net Zero: Leading-Edge Design and Construction of Homes and Buildings for a Renewable Energy Future

Bensonwood is featured prominently in a new book on Net Zero building by renowned architect William Maclay. We collaborated with Maclay Architects as a member of the team which designed and built the award-winning net-zero Bosarge Family Education Center at the Coastal Maine Botanical Gardens. The LEED Platinum-certified center was Maine’s first net-zero institutional building.

bill maclay

WILLIAM T. MACLAY, AIA, NCARB, LEED AP

The new threshold for green building is not just low energy, it is net-zero energy, and in The New Net Zero, sustainable architect William Maclay charts the path for designers and builders interested in exploring green design’s new frontier—net-zero energy structures generating as much energy as they use while remaining carbon neutral.

Since traditional American buildings account for roughly 40 percent of our total fossil energy use, the significance of net-zero building is growing increasingly important—among designers interested in addressing climate change as well as homeowners concerned about energy efficiency and long-term savings.

coastal maine botanical gardens

The Bosarge Family Education Center at the Coastal Maine Botanical Gardens. Photo by Robert Benson

Maclay, an award-winning net-zero designer whose buildings have achieved high-performance goals at affordable costs, makes the case for a net-zero future; explains net-zero building metrics, integrated design practices, and renewable energy options; and shares his lessons learned on net-zero teambuilding with like-minded companies such as Bensonwood.

The comprehensive overview is accompanied by several case studies, which include institutional buildings such as the Bosarge Family Education Center, commercial projects, and residences.  Both new-building and renovation projects are covered in detail. Unity Homes is profiled in the book, as is our multi-layered Open-Built® system.

The New Net Zero is geared toward professionals studying net-zero design, but is also suitable for laypersons seeking inspiration and strategies for beautiful and renewably powered net-zero options.

Our Building Systems Flawless in 3rd Party Inspection

2014.01.16_Panel shop (25) - Copy Four times a year, TR Arnold, a respected third-party “in-plant inspection agency,” or IPIA, is authorized by us to conduct unannounced inspections at our Blackjack Crossing production facilities. In voluntarily submitting to TR Arnold’s findings, our intention is to ensure that construction standards (state & local code, as well as our own stringent standards) are consistently adhered to.TR Arnold

Essentially, TRA inspectors go through each of our work stations inspecting up to 120 certification elements. As part of this quality control process, TRA inspectors are authorized to, “…reject non-compliant units, to withhold labels and to inspect all finished units produced and labeled prior to a unit found deficient and subsequent to the last unit inspected at the station where the deficiency occurred.”

One such audit has just concluded, and we’re pleased to report that of the many assemblies inspected, no non-conformance issues were discovered and we were found to be in complete compliance.

According to Building Systems specialist, Scott Bosworth, “This is really a big deal because of our building techniques compared to other, very different kinds of prefab home builders. For example, with “Double-Wide” manufactured homes that travel down the highway in halves, there are only two certificates required: one for the left side of the house, and one for the right side. With our many panelized assemblies (that are later raised at the build site), there are 120 or more certification elements that can be inspected prior their leaving our production facilities.”2014.02.07_Panel shop (8)

As Scott elaborates, “And because of the kind of closed-panel, or closed-cavity assemblies we fabricate offsite, building inspectors at the home site appreciate seeing certifications created by independent, in-plant inspectors who have seen the panels come together at the point of manufacture. Therefore, getting a full compliance report from a third-party administrator is huge,” adding, “A perfect score from a company like TR Arnold not only helps affirm our own quality control efforts, but in some cases, having the certificate can also help reassure a local on-site building inspector regarding enclosed areas he or she cannot readily see into.”
2014.02.07_Panel shop (2) - Copy
According to Bensonwood/Unity Homes production head, Kevin Bittenbender, who is in charge of compliance control and was instrumental in setting up independent plant oversight, “We’ve been building to the highest quality standards for years. It’s just what we do. It wasn’t much of a change in our process, or product, to meet TR Arnold’s standards. We simply had to clearly explain and document our product, and how we work. Our standards are higher than what is needed for code, and receiving positive results from their inspections is a nice confirmation that we are successfully building to the highest standards in the industry.”