Passive homes such as the GO Logic model house in Belfast, Maine, are still rare in America, but forward-thinking homeowners, builders, and architects are increasingly incorporating the strict German standard in new homes.

This weekend the New York Times highlighted the growing effort of architects, builders, and homeowners to create houses that meet the strict German Passive House standard.

The article, Can We Build in a Brighter Shade of Green?, follows the story of one super efficient home built in Vermont.

It notes both the challenges both with designing such an efficient house, and getting the required skills and materials to construct it in America:

While some 25,000 certified passive structures — from schools and commercial buildings to homes and apartment houses — have already been built in Europe, there are just 13 in the United States, with a few dozen more in the pipeline.

“Even though the passive house standard is tried and true, and is used all throughout Europe — we know it works, we know there’s some simplicity to it,” says Mrs. Landau, “here in the United States, we were reinventing the wheel.”

… In Europe, this design-and-construction balancing act has an established manufacturing base to feed it; in the United States, not so much.

“If we were in Europe, most of the materials and equipment would be off-the-shelf and readily available from local suppliers,” says Tedd Benson, owner of Bensonwood Homes, a high-efficiency timber frame builder based in Walpole, N.H., that is constructing the Landau house. “And they would have already been vetted and certified by the Passivhaus Institut, with their performance specifications already linked into the passive-house software.

“Here, we have to invent the systems and try to find the materials, products and equipment that will help us meet the passive-house standards.”

Despite an initial price premium (for additional design time, thicker walls and insulation), over the course of its life a Passive House will return the initial investment many times over. The Landaus (featured in the Times article) expect to have the energy efficiency investments pay for themselves within 10 years.

Here’s a video the Times produced on the project:

Journalist Tom Zeller Jr. went on to write about the general state of green building in a follow-up blog, When Green Building Is Not Green Enough.

In it, he cites design-focused (rather than energy-focused) architecture as one of the problems with building design, stating that “American architects are well schooled in matters of design, they often receive little training in the physics of how a structure breathes, how it consumes energy and how best to elevate its overall efficiency.”

While it is an accomplishment to see that “more than 1 million Energy Star qualified homes, which consume at least 15 percent less energy than conventional construction, have now been built in the United States,” Zeller goes on to say the “lack of [more] ambitious targets may actually be hindering the effort to address pressing problems like global warming.”

Why Code-Built is Not Efficient Enough

To understand why exceeding Energy Star ratings is desirable, Zeller includes a graphic of the HERS Index, a chart that shows the energy consumption of typical homes on a scale from zero to greater than 100, showing how different types of construction stack against each other.

Here’s the graphic, courtesy of Zero Energy Design:

We express the discussion in slightly different terms. Here’s a graphic from our renewable home heating page, where we frame the discussion of mechanical systems for heating a home in terms of btu/hrs required per square foot:

The underlying principle remains this: the more energy efficient a home is, the less heating load it requires. When minimal heating load is required, smaller, modest, and renewable heating options make sense, and monstrous fossil fuel heating systems are unneeded and uneconomical.

Going Passive in Maine

ReVision has worked on a number of high performance homes, here are links to a few:

• The GO Logic home in Belfast, Maine is the state’s first true passive house home. The prototype home has produced more energy than it has used to date and is a model for a new Belfast cohousing community.
• The home of architects Ian and Zofia Weiss uses many passive house principles. It uses radiant heat powered by solar hot water collectors with electric backup, and should eventually have grid-tied solar electric to make it near net-zero.
• The Bright Built Barn is a net-zero home in Rockland that incorporates leading-edge building practices and an innovative LED system to inform you as to whether the home is generating more energy than it is using.

The sun will be the star of this all day event held at Gritty McDuff’s in Freeport, Maine. Join WCLZ, Gritty’s and ReVision for solar tours and demos, prizes, children’s activities, and of course, great brew.

Gritty’s new solar how water system will provide a substantial amount of the water used in their restaurant and brewpub, and we’ll be giving tours throughout the day showing you how it works.

Here’s a promo of the (free!) event you’ll hear on WCLZ:

Join ReVision Energy at the Common Ground Fair in Unity, Maine, the again be at the Common Ground Fair in Unity, Maine. Managed by the Maine Organic Farmer and Gardner’s Association (MOFGA) the Common Ground Fair is Maine’s premiere showcase of local, organic foods and sustainable living.

The Fair consists of hundreds of vendors, exhibitors and demonstrators, more than 1,000 volunteers, and tens of thousands of fairgoers who gather to: share knowledge about sustainable living; eat delicious, organic, Maine-grown food; buy and sell beautiful Maine crafts and useful agricultural products; compete in various activities; dance; sing and have a great time.

A full schedule of events is available on the fair’s website.

The fair runs September 24 – 26, gates open at 9:00 am each day and open until 6:00 on Friday and Saturday, 5:00 on Sunday. Tickets are free for MOFGA members, $10 for other adults, $8 for elders and free for children. Buy tickets at the gate or at these local vendors.

See you in Unity!

The Bar Harbor Times Soup reports on a unique rammed-earth house constructed in Salsbury Cove this summer. ReVision installed the solar electric and solar hot water system on the home which expects to have net-zero electric use due to high solar production in the summertime.

Laurie Schreiber writes:

Retired professors, Turner and Karnaky wanted their second home to be as energy-efficient as possible. Turner said she learned about the rammed earth technique years ago. After considerable research into alternative building methods in general, she said rammed earth emerged as the best choice for the first story. In 2000, the couple approached Sassaman, whose portfolio ranges from detail work to high-end residential construction, additions and renovations. The design was finalized in June 2008 and excavation began that August.

… Minimum energy use is the order of the day, with the use of low-energy appliances, triple-glazed windows, radiant floor heat, and composting toilets. Turner said she expects that the photovoltaic system will generate enough electricity in the summer to sell some back to their grid provider. In the winter, the house will consume electricity to keep the house from freezing, but the energy usage should zero out, she said.

Read more (PDF Download)

This workshop will provide hands-on, real world exposure to a deep energy retrofit project in process. The workshop will take place at a residence in Falmouth, Maine which is undergoing a deep energy retrofit with the goal of becoming a net zero energy building. The workshop will include in-field exposure to core techniques in deep energy retrofit as well as identification of the unexpected and unique issues that arise when actually applying deep energy retrofit techniques in a real rather than “ideal” case. Participants will visit the site at four intervals during the building process for in-depth tours and instruction. Each site visit will last approximately two-hours.

Faculty:

• Phil Kaplan and Richard Lo/ Kaplan Thompson Architects
• Dan Kolbert/ Kolbert Building and Renovations
• Ann Kearsley/ Ann Kearsley Design Landscape Architecture and Urban Design
• Fortunat Mueller/ ReVision Energy
• Jim Godbout/ Jim Godbout Plumbing, Heating and Air Conditioning

The workshop consists of four different visits to the site – you can learn more about the workshop with a free tour of the project site from 4:30 to 5:30 PM on September 22.

See the Maine Chapter of the USGBC website for more details.

The elegantly and minimally designed home of Ian and Zofia Weiss is heated nearly entirely from the sun.

Photo courtesy of locative DRD

What defines a home? The materials it is made out of, or the human experiences that happen there?

For Ian Weiss and Zofia Weiss, a home is a combination of both. In 2008, the husband of wife team, founders of locative Design Research Development, started on a journey to build a new home and office for themselves that would combine two different, but not antagonistic ideas:

• The Rational House – Designed and built to efficiently endure Maine’s climate for the next century
• The Emotional House – Designed to serve socialization between people and interaction with place

They write:

An energy-efficient house appeals to a person’s rational side. It does more with less. It requires less energy, thereby reducing the burden on the owner of securing, paying for, and shouldering the consequences of that supply … Working among the various ideas surrounding sustainable architecture, we came to the conclusion that energy use should be the primary measure of whether a house is “green” or not … An energy-efficient house’s savings over its lifespan CAN outweigh all other choices a person makes regarding energy use.

Yet, a home is more than the sum of its parts:

The architecture facilitates a way to sit and read, to observe the outdoors beyond, to enjoy the sun … The Emotional house concept as we perceived it … was built on favorite moments in houses and apartments we lived in, exciting features we came across in houses of friends we visited. It was the settings of our most emotional memories, indoors and out, the places that served as the backdrops and stage sets for the actions of people. It was angles of sunlight in the morning and afternoon, the warmth of a kitchen.

Solar Heating as a Solution

“Our primary goal was to build a new house of our own design that did not rely on fossil fuels,” writes Ian Weiss. “It became obvious early on that a super-insulated house would require only a small heat source, which opened the door for employing solar hot water for space heating as well as domestic hot water. The combination of solar hot water with in-floor radiant heat was a perfect fit that would provide the majority of our heating.”

The keys to a successful solar space heating system are a super-insulated building envelope, excellent southern exposure, and low temperature distribution (i.e. radiant floors vs. radiators). The Weiss’ included all of these aspects in their design, with R values of 50-58 throughout the structure and a perfect southern orientation on their home (which also helps with the Emotional side of the house – providing ample sunlit areas to work and live during the day).

Due to the high insulation value, the heating needs of the space are low, which means that solar thermal is viable as the home’s primary source of heat. In deep winter, when the sun is at its weakest and the heating needs are at their highest, the energy gap is made up with seamless electrical backup, as well as locally harvested wood.

The Weiss’ created this useful graph for understanding this energy gap when compared to a conventional home:

Solar Space Heating Design

The great part about solar hot water space heating is that the same system provides all of the home’s domestic hot water.

The system we designed and installed consists of a 120 evacuated tube hot water array tied into two solar hot water storage tanks. When the temperature at the collectors is hotter than the tank, the pump begins to circulate a non-toxic food-grade antifreeze solution through the collectors and into the heat exchange coils in the storage tanks.

Should there not be enough sun to heat the domestic tank to its set point, the integrated electric element turns on and provides automatic backup.

The Experience

“The installation was simple because our project was new construction,” says Ian. “The design phase went smoothly with ReVision trusting us to handle energy modeling and to determine a design load we were comfortable with. Easier than expected? Yes.”

Now he and his wife are living in the home and starting to enjoy the more emotional parts of the experience:

When the sun shined, our solar array made hot water, even when it was 15 degrees Fahrenheit outside. We were thrilled to be so warm. Yet, the Rational House’s performance in the winter conditions told half the story of our satisfaction with it. The Emotional House was the one we really lived in, wrapped inside an energy-efficient super-insulated rational shell.

Learn more from their profile of the 57 Union St, Belfast home, or see Locative DRD’s website.

From our Residential Solar Photo Gallery:

For more installations, see our Solar Projects Map

This 4.8kw solar electric system in Meredith, New Hampshire benefited from the $6,000 cash rebate. 1.4 megawatts of solar electric were installed during the course of the program, enough to offset 2.5 million pounds of C02 each year, the equivalent of removing over 200 cars from the road, or planting more than 6,000 trees.

As expected based on order of notice DE10-194 and the pursuant public hearing (see our coverage here), New Hampshire has reduced their residential solar electric rebate.

In the original notice, the expected drop was from $3/watt, $6,000 max to $1.5/watt, $3,000 max. The drop was not as dramatic as original anticipated. Instead, the new rebate structure is $1.25 per watt up to a maximum of $4,500.

Here is Jack Ruderman, Director of the NHPUC’s Sustainable Energy Division, on the change:

Simply put, the program has been so successful since its inception in July 2009 that we have effectively exhausted our funding for the current state fiscal year (which ends June 30, 2011). To date we have received 473 applications requesting a total of $2.7 million to install systems with a combined capacity of 1.4 megawatts. The combined value of these systems is $9.6 million, resulting in leverage of nearly $7 million in homeowner funds … Consequently, the Commission issued an order this afternoon reducing the incentive level to $1.25 per watt up to a maximum of $4,500 or 50% of eligible system costs …

We will continue to offer our residential solar hot water rebate program, a well-funded program offering generous state and federal rebates, and a residential wood pellet heating rebate program offering rebates of up to $6,000. In addition, we will soon be offering a commercial and industrial rebate program for solar electric and solar hot water systems, and this winter we will issue a Request for Proposals to offer funds for renewable energy projects on a competitive basis. As more funds become available we will look to offer rebates for additional renewable energy technologies. Our mission is to offer an array of financial incentives for those who are ready to invest in a clean energy future.

We appreciate Ruderman’s upbeat attitude, particularly in regards to pushing the upcoming commercial and industrial rebate program. We’re eager to see how New Hampshire is able to encourage businesses to lock in their utility rates and offset their C02 emissions.

For full information on the changes, see the full Order DE 10-194 (PDF).

How Does This Affect The Affordability of Solar Electric?

Even with the reduced cash rebate, purchasing a solar electric system locks in an electric rate better than what’s offered by the utility.

Here’s a modified version of our chart from our original post, PV Costs Less than Grid Electric – Even at Today’s Prices:

Taking the long view, solar electricity is still an excellent investment – one that will provide tens of thousands of dollars of energy savings over its first 25 years and probably will continue to operate for nearly double the lifetime calculated here!

Stay tuned here for news about the business and industrial rebate, we’ll post it as soon as we know, probably the same day the order is given.

Join us, along with the Maine Chapter of the U.S. Green Building Council, for a tour of the LEED Platinum Redfern House!

The Redfern House is an outstanding example of a home that is truly healthy, extremely efficient, highly durable, and ecologically and socially responsible.

This innovative home, located on an in-fill lot in Portland is one of only several “Platinum” rated homes in Maine, but is perhaps more distinguished by its combination of comfort, efficiency, design and relative affordability.

The 3 bedroom, 2.5 bath home was designed to be highly functional, making maximum use of its 1700 square feet, and featuring thoughtful spaces and attractive finishes. Requiring no fossil fuels, the home relies largely on its solar systems (both a Solar Thermal and a Photovoltaic system) for energy. Extremely inexpensive to operate and maintain, the Redfern House was built to demonstrate that “green” building principles, when properly applied, can lead to smart and economical residences.

The homeowners, developers and architect will be on hand to provide details and answer questions about this green home. Refreshments will be provided.

The cost to attend the tour is $10 for USGBC Maine Chapter members, $12 for non-members. To register for the event,  visit the Maine Chapter of the U.S. Green Building Council’s website.