Passive House: The House of the Future | Sheri Koones

Passive House: The House of the Future | Sheri Koones

smaller_version_400x400Posted: 05/08/2014

From our old friend Sheri Koones in the Huffington Post yesterday. We appeared in prefabulousher popular 2012 book Prefabulous + Almost Off the Grid: Your Path to Building an Energy-Independent Home.

The Passive House (or Passivhaus) (PH) was first established in Germany and is quickly becoming a standard in many parts of the world, including the United States. Whereas other important standards, such as LEED), focus on many environmentally friendly aspects of the home, such as site location, sustainability, materials, water efficiency and so on, Passive House only focuses on energy and ventilation.

Inspiring and Building the Next Generation of Residential Energy Professionals

DOE STUDENT CHALLENGE DESIGN AWARDSThe Challenge Home Student Design Competition seeks to inspire the next generation of architects, engineers, construction managers, and entrepreneurs to design homes that meet requirements for zero energy ready performance that are affordable and market-ready. In turn, the competition provides students with skills and experience for careers in clean energy.

This week, the U.S. Department of Energy announced today the winners of the first competition. The winning teams produced market-ready, state of the art design solutions for high-performance homes that are energy efficient, comfortable and durable. The designs are for zero energy ready homes, meaning their high performance features sharply reduce energy use and all or most of the remaining energy use can be offset with renewable energy.

MONTAGE DESIGN TEAM WINNERSWe are honored that one of the winning teams, Montage Builders – Northern Forest, thanked Tedd Benson and Bensonwood Head of Engineering Chris Carbone for inspiration and support. Tedd and Chris met team members and SUNY – ESF students Michelle Tinner and Peter LiCongo recently at the NY Green Building Conference where he was a keynote speaker and Carbone led a session on “Designing and Building with Heavy Timber.”

Montage Builders – Northern Forest student team leader Michelle Tinner describes her team and their influences this way:

“We were very inspired by Tedd’s use of the word montage. Here is how we define the term as it relates to our team name: Montage Builders – Northern Forest. Montage, a combination of different elements that forms a unified whole, references our teams diverse multi-cultural and multi-generational aggregation of perspectives and experiences, which is the key for the success of our design.

Northern Forest acknowledges the importance of regionally specific design and the default (pre-development) landscape of our region – used for accurate site ecosystem service assessment.

Our team was unique in that we brought together students and faculty from three different educational institutions – all other teams represented just one. We also integrated may different disciplines which supported our holistic approach. We have communications designers, interior designers, architects, landscape architects, environmental scientists, engineers, and construction managers on our team.

An important parallel between Tedd Benson’s approach and our’s is the use of natural materials, the reliance on traditional ecological knowledge, and the reference to historically relevant architecture. We used American Craftsman style architecture which was popularized by a local designer Gustav Stickley. The style is inherently honest and promotes the use natural materials like wood, which is locally available and environmentally preferred, it discourages functionless additions such as fake dormers (the McMansion’s failed attempt at not looking silly), and can be found throughout Syracuse’s neighborhood ensuring that our design would fit the local pattern language. Many of the other designs at the competition were modern.

We were all delighted to have Tedd attend our presentation at the New York State Green Building Conference. He smiled at us the entire time we were up there presenting – probably because he was pleasantly surprised that we were using his favorite word. Having his support and that of Chris Carbone, who got us a timber framed pergola quote at the 11th hour was encouraging and meant a lot to us.”

DOE CHALLENGE HOME LOGOThe team was led by three faculty advisors: Paul Crovella, Ken Bobis and Kevin Stack.

Right now, there’s a need to develop cost-effective designs that are at least 40-50% more efficient that a standard new home. These homes are so energy efficient they offset all or most annual energy consumption with a renewable energy system, such as solar.

To support this increased demand, the Energy Department’s Building Technologies Office is helping to develop a strong workforce with core competencies in building science, including direct entry workers, recent college graduates, and those in continuing education through a number of high-impact initiatives and programs, such as the Guidelines for Home Energy Professionals, Solar Decathlon, and the Energy Department’s Challenge Home Student Design Competition.

What One Modern House Tells Us About the Future of Urban Building – Next City

via What One Modern House Tells Us About the Future of Urban Building – Next City.

On a Tuesday morning not long ago, I entered a half-assembled house tucked into a quiet corner of Somerville, Mass. In much of this small city, adjacent to Cambridge, you can no longer walk down the block without passing a yoga studio or an artisanal butcher. But this residential street still felt more like the blue-collar town of a previous generation. Outside, a yellow crane lifted a floor deck high overhead. A few men wearing hard hats and tool belts busied themselves inserting screws and climbing ladders. MORE

LEED Platinum-Certified Bensonwood Project Wins 4th Award

A view of the Burr and Burton Mountain Campus Academic Building as you approach from the road.

A view of the Burr and Burton Mountain Campus Academic Building as you approach from the road.

The LEED Platinum-Certified Burr and Burton Academy Mountain Campus in Peru, VT, which Bensonwood designed, engineered and built, is a recipient of the 2014 Governor’s Awards for Environmental Excellence.

Environmental excellence awards have been given since 1993 to recognize efforts and actions of Vermonters to conserve and protect natural resources, prevent pollution, and promote environmental sustainability. To date, more than 200 efforts have been recognized.

“These projects contribute significantly to Vermont’s environmental quality and encourage others to take similar actions to protect our resources,” said Deb Markowitz, Secretary of the Vermont Agency of Natural Resources. “They demonstrate the importance of innovation and partnerships in enhancing and sustaining Vermont’s environmental quality.”

Award winners will be recognized at the Vermont Businesses for Social Responsibility Annual Spring Conference on May 14 at the Davis Center on the University of Vermont campus in Burlington.

front of BBA's mountain campus by Bensonwood

The front entrance of the LEED Platinum-certified, net-zero energy building.

This is the fourth award in the past four months for the building. BBA’s Mountain Campus also won Efficiency Vermont’s 2014 Better Buildings by Design “Best of the Best” in Commercial Building Design and Construction, recognizing innovative and integrated design approaches for energy efficiency in Vermont’s commercial and residential buildings.

BBA Heater

The ultra-efficient masonry heater in the school building is integral to warming the building.

In November, the Mountain Campus earned a prestigious Engineering News-Record “Award of Merit” and in January 2014, it won the “AIA New Hampshire Merit Award.” The AIA jury said: “The respect for the environment is as integral to the architecture as it is to the mission of the school. The jury appreciated how the structure, columns, and framing define the composition and are a metaphor for the forest setting.”

Like Unity Homes and other Bensonwood custom timber frame projects, the building was largely prefabricated offsite and erected quickly in the forested setting to minimize impact to the local ecology.

Passive House Wins Award for “Best Energy-Efficient Project”

Steven and Barbara Landau’s Norwich, Vermont, Passive House won The Builders and Remodelers Association of Greater Boston (BRAGB) Prism Gold Award for “Best Energy-Efficient Project.” Bensonwood, who designed the prefabricated insulated panels and constructed the timberframe shell, was honored as part of a highly-skilled green building team that included energy modeling and mechanical consultantsZeroEnergy Design, consulting architect Paul R. Bilgen, general contractor Estes and Gallup, and custom window and door maker, Architectural Openings. The innovative, sustainable home previously won the 2012 Efficiency Vermont “Best of the Best in Residential New Construction” Honor Award.

The 17-inch recycled foam sheet insulation provides R-75 value and a vapor barrier below the slab. All hot water is provided by two rooftop, flat-plate solar collectors with an electric on-demand water heater for backup. One kilowatt heating mats located under floor tiles in the bathrooms supply radiant heating, and air exchange is managed by a Heat Recovery Ventilator whose operation automatically adjusts, depending on temperature, humidity, and occupancy. In the kitchen/living room a sealed combustion chamber wood stove serves both as cooktop and bake oven, as well as a source of supplemental heat. The eco-friendly 2,457 square foot home also earned 41 Home Energy Rating index points, meaning it is 59% more efficient than a standard new home.

BRAGB, a trade association affiliated with the National Association of Home Builders and Home Builders Association of Massachusetts, has represented the building industry since 1944 and is one of the leading trade associations in New England.

Why We Use Dense-Packed Cellulose Insulation

Bensonwood's proprietary OBPlus Wall

A cross-section of Bensonwood’s cellulose-filled OBPlus Wall®.

Many have asked us why we use dense-packed cellulose insulation in our OBPlus Wall® panels, roofs and some ceilings and floors. Here are some of the cellulose advantages in our “Montage Building” system:

  • Our cellulose insulation is made from recycled newspapers treated with a natural mineral borate to give it a Class A fire rating as well as resistance to mold and pests.
  • The dry cellulose is blown into all the framing cavities at a settle-proof density (dense-packed), filling any shape with a continuous thermal insulation layer. The blowing process compresses the cellulose to a density of between 3 and 4 lbs/cu.ft. In addition to preventing any settling of the material, the dense-packed cellulose also cuts down convection that can occur around batt type insulation and in low-density blown fiberglass, particularly in colder temperatures.
ob plus wall with dense packed cellulose

Cellulose being blown into a Bensonwood wall panel.

  • Dense-packed cellulose blocks air movement better than fiberglass batts. While sprayfoam also seals the enclosure against air infiltration well, its rigid consistency when cured may allow it to crack as framing members around the insulation dry and move over time. Cellulose has the flexibility to allow for such movement without resulting gaps.
  • Similar to wood fiber, paper cellulose fiber manages moisture well, taking in and releasing the moisture effectively. As a result, indoor relative humidity is much more even due to the hygroscopic buffering capabilities of the cellulose insulation. This is in contrast to the hydrophobic characteristics of fiberglass and foam insulations, which lack this capability and can cause a home’s interior to experience significant swings in humidity when weather changes. So, with its tremendous insulating and moisture management characteristics, cellulose helps to buffer temperature and humidity extremes.
  • While foam insulation has a slightly higher R-Value per inch, cellulose takes less energy to manufacture than any other insulation material. This embodied energy includes the total energy required to transport the raw materials, then manufacture and distribute the finished product. Fiberglass has up to 10 times more embodied energy than cellulose and foam products have as much as 64 times more.
  • Cellulose insulation is one of the greenest building products, having the highest level of recycled content in the insulation industry—as much as 85%. Fiberglass has a maximum of 40% recycled content and foam products little or none.
  • Cellulose sequesters carbon in a building’s components instead of releasing it into the environment. Cellulose insulation is made from recycled paper that might otherwise end up in landfills, releasing methane as it decomposes, or be burned, releasing CO2. This sequestration results in a positive carbon balance which helps the efforts to lower the material’s impact on climate change.
  • Cellulose insulation is produced regionally, employing local recycling programs and independent recyclers.
  • While all insulation provides sound reduction, cellulose has approximately three times the density of fiberglass as well as fibrous consistency, delivering enhanced sound dampening.

For more details on cellulose insulation, visit http://www.nationalfiber.com/cel-Pak.htm or http://cellulose.org/GreenestInsulation/.

What dense-packed cellulose looks like inside a wall.

What dense-packed cellulose looks like inside a wall.

Solar Unity Home, Contract to Complete in 20 Weeks

A year ago when Carol and Ed Reardon wanted to build a healthy, energy-efficient, year-round residence on a lake, they knew whom to call.Bensonwood had recently launched its sister company, Unity Homes, which offers healthy, high-performance, more affordable homes.  Here was their chance to own a high-quality Bensonwood home on a budget they could afford. Best of all, they discovered they would be living in the home in only five months’ time.

The home, a Xyla 132, is the first Unity home to feature solar electric panels, which power the HVAC system, including an air source heat pump for both heating and cooling, and heat recovery ventilation. Because of the extremely low energy demands of the Unity building shell (the highly-insulated homes meet or exceed Passive House levels of air tightness), and with the state and federal incentives, the solar panels by Solar Source made sense financially.

Unity Homes Xyla Floor PlanThe home site, on a picture-perfect lake in southern New Hampshire, had been in Carol’s family for decades, so she became the driving force behind the project. The first step was to remove the old camp sitting on the land with serious rot and mold in the crawl space and above the ceilings.

Unity Homes Xyla open floor planCarol was particularly interested in the health aspects of Unity homes. Living with allergies, she wanted cabinets and vanities with low VOCs (volatile organic compounds), wood construction and a sophisticated ventilation system. All Unity homes share these health benefits, along with solid, light-filled, quiet spaces that promote a sense of well-being.

Carol says, “Unity came along at the right time for us. We have downsized to a beautiful new home where we can enjoy our retirement years in a place we love.” Ed Reardon adds, “Bensonwood and Unity people have been a pleasure to work with throughout this process. Special praise goes to Unity project manager Ryan Lawler who couldn’t have been more helpful, responsive and encouraging.”

Five Star Rating for Unity Home

We have received some fantastic news about the exceptional performance of our Unity Homes.

Rear Exterior of Vermont Xyla (Photos taken May 2013, Landscaping not complete)

Rear Exterior of Vermont Xyla. This home received a 5 Star Plus Certification for excellence in energy efficiency, is 56% more energy efficient than a home built to current code and 86% more efficient than the average American home. (Photos taken May 2013, Landscaping not complete)

We recently completed our first Unity Home, a Xyla in southern Vermont.  The home was tested by Efficiency Vermont for compliance with the Vermont Residential Building Energy Standard (VT-RBES). The 2,376 sq. ft. home with conditioned walk out basement achieved a Home Energy Rating System (HERS) score of 44, receiving a 5 Star Plus Certification for excellence in energy efficiency.

So what does that mean to a home buyer?

It means this home is 56% more energy efficient than a home built to current code and 86% more efficient than the average American home.  

This home also tested at 0.51 ACH50!  This number is so extraordinarily low that it surpasses the Passive House standard of 0.6 ACH50.

So you don’t have to take our word for it – the numbers show our Unity Homes continue to exceed the energy performance of other homes built to code.

New Tools for Calculating Energy Usage in Net Zero Homes

Over the years at Bensonwood we’ve designed and built a number of LEED certified, Net-Zero homes and commercial buildings, but our team never stops in our quest to learn more, and deliver new and better design/build methods to the benefit of our clients, our world and our structures.

(Some noteworthy projects: Unity House which partially informed and inspired our new Unity Homes brand, the Net-Zero Coast Maine Botanical Gardens, and Burr and Burton Academy* which we recently blogged about).Rheannon DeMond

Bensonwood Assistant Project Manager Rheannon DeMond recently completed the Net Zero Energy Homes 10 week course as part of the NESEA Building Energy Masters Series that covered every aspect of designing a Net Zero Energy Home.  Rheannon has a background in building energy performance but was looking to further educate herself on the necessary calculations, systems and technologies that it takes to design a home for Net Zero Energy use.

(Read a post by Marc Rosenbaum who taught the course, on his Thriving on Low Carbon blog).

“What the company and myself got out of this course was a set of excellent calculation tools to make estimating all aspects of energy usage much easier.  We are now capable of estimating the total energy usage for a home in the North East, and the size of the Photovoltaic array that can handle those loads to make a home Net Zero capable.  The tools will also allow us to analyze current designs to show home owners the advantages and disadvantages of certain systems and orientations.  As a company that is always striving to be more efficient, this course has given us the additional information and tools to allow us to better design homes that will continue to save our clients money and reduce their impact on the environment.”

Please join us in congratulating Rheannon on completing the course.  Her expanded knowledge will benefit both Bensonwood and our clients!

*Note: Burr and Burton Academy’s Mountain Campus academic building was designed/built to achieve Net-Zero energy status and LEED Platinum certification but has not yet been certified.

Burr and Burton Academy

A view of the Burr and Burton Mountain Campus Academic Building as you approach from the road.

A view of the Burr and Burton Mountain Campus Academic Building as you approach from the road.

At Bensonwood we’re proud of our nearly 40 year history as the premier designer/builder of energy-efficient timber frame, hybrid, and other high-performance homes.

But we have also built a strong reputation for designing and building LEED certified, energy efficient and architecturally striking commercial buildings and specialty structures.

Recently, Bensonwood Lead Architect Randall Walter and other members of our architecture and engineering team designed the Burr and Burton Mountain Campus Academic Building.

Dedicated on August 23, 2012 in time for the opening of the school’s fall semester, the building is designed to be a living classroom with a goal of achieving LEED Platinum designation and Net-Zero energy status.

BBA Heater

The masonry heater is a focal point within the “Clearing” in the Mountain Campus Academic Building

Randall worked closely with the Burr and Burton team to ensure that the building not only fit into the natural surroundings of the site but truly became part of the learning experience for students, blending scientific architecture with artistic abstraction. Design features include ceilings inspired by the structure of the underside of a leaf, a skylight that casts light on the native Vermont slate clad masonry heater, between two reclaimed oak trees primary walls splayed at 14.5 degrees, celebrating the variation between true north and magnetic north in southern Vermont.

In keeping with typical Bensonwood design and construction practices, locally sourced materials where used wherever possible.

Speaking at the dedication ceremony Randall noted that a quote by Winston Churchill inspired the design – “We shape our buildings; thereafter they shape us.”

Below Randall has provided additional information on some of the features of the building:

Size

  • Primary building area: 4000 square feet
  • Total building including overhangs: 6200 square feet

Building Materials

  • Marvin Ultimate clad Triple glazed windows and doors (R-5)
  • Cellulose insulated walls (R-35) and roof (R-60)
  • Red Oak – log posts from Alstead, NH & BBA campus
  • Nordic-Lam – engineered timbers – Canadian black spruce
  • Eastern white pine – rafters & ceiling boards
  • White and red pine wall boards (red pine from BBA campus)
  • Hemlock – rough sawn, random width siding from NH and VT
  • Western cedars – exterior posts and beams
  • Sliding barn doors – reclaimed local barn board, oak frames
  • VT sourced maple benches and window sills
  • VT Shadow Grey slate tile
  • VT Verde Green brushed marble counters and hearth

Interior and Exterior Finishes

  • Vermont Natural Coatings – whey based finish – used on all wood and concrete surfaces
  • All finishes have low or no Volatile Organic Compounds (VOCs)

Performance

  • Wood burning masonry heater
  • Air-source heat pumps
  • Energy Recovery Ventilators for fresh air
  • Photovoltaic arrays (Sept/Oct install) to achieve Zero net energy
  • All plumbing fixtures exceed EPA water sense standards
  • Preliminary blower door test below Passiv standards for air infiltration (495cfm@ACH50)

Construction Schedule

  • Foundation installed November 2011
  • Prefabrication offsite over winter
  • Site access reopened April 2012
  • Delivery of prefabricated parts and assembly begins May 2012
  • Building completed in 4 months
  • Waste management plan exceeded LEED requirements – near 93% waste diversion
  • Anticipated LEED points 82-83 (Platinum threshold is 80)