Net-Zero Subdivisions
Green neighborhoods take root in Maine
By Tim King
HIGH-EFFICIENCY, SINGLE family net-zero and net-zero-ready homes (buildings that can generate as much energy as they consume during the year) have been appearing in Maine at a slow and steady pace for several years. One by one, skilled, passionate builders and self-motivated, green-minded individuals have built homes that are more energy efficient than anything on the market. These homes, many of which have been profiled in previous editions of Green & Healthy Maine HOMES, have dutifully demonstrated that such buildings can be built—and perform well—here in Maine.
Still, this relatively small number of high-efficiency homes has had little impact on the overall housing stock in Maine. According to Maine Housing, more than 60% of all homes in the state were constructed before 1980, long before concerns about energy use and climate change were in the news.
Yet, each one of these exceptional, energy-efficient homes has shed light on what can be built (when costs aren’t highly constrained) and has allowed builders to learn about new products and methods so they can construct better performing homes for an increasing number of Americans–of all income levels.
The Unity Homes at Douglas Ridge in Brunswick use Wasco, triple-pane (R7), European tilt-swing combo windows, all center-wall mounted for eciency and weather protection. Shown here, looking out over 280 acres of conservation land. Photo: Tim Greenway
To make an even greater impact on the big picture of housing quality in Maine (and our high dependency on fossil fuels for heat) more new, high-performance homes—built with proven energy-efficient construction methods—must become available, accessible and affordable for the typical Mainer to buy.
In the past, developers and builders have used the subdivision model to minimize building costs. By creating an environment that produces a more efficient use of machinery, labor and materials, builders can construct homes at lower costs, ultimately making each one more affordable for homebuyers.
Today, there are signs that some land developers are using the same subdivision model to lower the cost of building and owning a high-efficiency, low-energy home.
Shrinking the price/performance gap
Until recently, the process of designing, siting and building a highly-efficient home automatically came with a higher-than-the-average-new-home price tag. However, continued technological and manufacturing improvements have helped reduce the cost of many high-performance building products, such as breathable membranes, SIP panels, solar panels, windows and doors, making them more affordable for builders.
Houses at Baird Landing are all-electric with heat provided by heat pumps and solar electricity installed by ReVision Energy. The first two homes in the development were sold to families with young children. Photo: Tim Greenway
Here in Maine, builders now also enjoy easier access to a wider range of high-efficiency HVAC equipment and other products manufactured around the world, thanks to regional suppliers such as Performance Building Supply in Portland. Additionally, lower costs and greater availability of powerful home design and energy modeling software programs such as Revit, SketchUp and WUFI®Passive have enabled local architects and home designers to create (and easily replicate) plans for high-performance building components designed to deliver outstanding protection from site-specific, variable, external weather conditions. These efficiencies can reduce the amount of time, energy and expense of getting a new home design that is practically guaranteed to perform well.
Low cost solar is making net-zero more affordable
A major contributing factor to the speed at which a netzero homebuyer can expect a return on investment is the cost of adding solar electric panels to their home. Over the past several years, the cost of solar has dropped significantly, while energy rates continue to rise.
According to solar industry news source Energy Sage, the average gross cost to install a “standard” 6 kW home solar system has fallen from $52,920 in 2008 to $18,840 today. At $3.14 per watt, that’s a reduction of more than sixty percent in 10 years.
The National Bureau of Economic Research also found that solar PV systems “add 3.6% to the sales price of a home. This corresponds to a predicted $22,554 increase in price for the average sale with solar panels installed.”
Great homes & greener neighbors
Across new housing developments, like-minded individuals are creating neighborhoods of homes that not only tread lightly on the land they occupy but also generate enough of their own clean energy—typically through solar PV panels— to help further reduce the impact fossil fuels have on the environment.
While several macro issues such as the Maine job market, the U.S. economy and the “premium perception” associated with green building helped stymie some earlier efforts to create energy-efficient housing developments, the new series of net-zero developments is telling a different story. Baird Landing in Freeport, Douglas Ridge in Brunswick and the more established Kelsey Brook—also in Freeport—all model a promise of affordable net-zero living.
Baird Landing - doing it their way
One way these developments are keeping building costs down is by owning more of the process.
Typically, within most subdivision construction projects, numerous companies are involved in turning an empty parcel of land into a neighborhood filled with new homes.
A developer will hire a general contractor to oversee a team of site designers, architects and builders to handle specific stages of construction.
While this frees developers from delving too deeply into the details of any one project (allowing them to spend more time on their next one), it also adds to the cost of building each home.
Jonathon Lobozzo, one of the developers of Baird Landing, shows o the third home in the development and explains plans to add seven more in the next two years. Photo: Tim Greenway
To minimize these costs as much as possible, the owners of Baird Landing, an open space sub-development located on 30 acres of woodland in Freeport, made a conscious decision to do most of the work themselves.
Jonathan Lobozzo and Alex Burnham, childhood friends who are now business partners, have long been interested in high-performance homes and began formalizing ideas on ways to make them more affordable to build.
Their company, Burnham & Lobozzo Builders of New Gloucester, bought a large parcel of land a few years ago that was purposely located away from the pricier Maine coastline yet still offered easy access to major roads and amenities within the town of Freeport.
“From the beginning, we decided that if we were going to do this, we were going to do it right,” recalls Lobozzo. “We only wanted to build homes that we could really believe in.”
To that end, the homes at Baird Landing are built using post and beam framing that’s encased with thick panels of rigid insulation, creating what Lobozzo calls a “giant cooler,” protecting whatever is inside the box from feeling the effects of temperature changes outside the box.
Burnham & Lobozzo Builders accomplish this “cooler” by creating a continuous, air-tight, well-insulated outer shell, complete with R-35 exterior walls and a R-65 roof supported with a 6”x6” hemlock post and beam frame—built with sustainably sourced timbers. Once built, standard 2”x4” interior walls are constructed from within and connected to the exterior frame.
Combining the best building practices
Instead of adhering to any one standard of high-efficiency building practice, the company is focusing on creating high-performance, low energy homes that can be comparably priced to existing homes in the same area.
“We’re trying to start a trend where people begin to see that building low energy, net-zero homes cost-effectively is actually possible,” says Lobozza.
The home designs available at Baird Landing vary from 1,200 sq. ft to 2,200 sq. ft with up to four bedrooms and 2.5 baths. Exteriors are clad with durable, low-maintenance materials and metal roofs.
Highly efficient electric heat pumps maintain comfortable temperatures within each home, which are powered by grid-tied solar panels installed by ReVision Energy.
Built with purpose and performance in mind
The homes at Baird Landing are purposely designed without basements, which have historically been a leading contributor to heat loss in a home. Homeowners may be surprised to learn that 12” of concrete has the same R-value as a single pane of glass. If not properly insulated and air sealed— something that homebuilders have recently begun doing in earnest—cold air infiltrating into a basement can significantly increase the amount of heat that’s pushed up and out of a home during winter.
Instead, the homes at Baird Landing are situated on a heavily-insulated concrete slab sitting atop a 5’ frost wall, in-filled with sand, creating a highly efficient foundation that is also less costly to build.
Each piece of lumber used in the framing process is precisely cut according to the plans created by Burnham and Lobozzo. Based on the cut list they provide, a local lumber yard cuts, labels and delivers the material (unassembled) to the job site, minimizing both waste and transportation costs back and forth from the lumber yard.
Baird Landing also seems to be bucking the belief that only downsizing empty-nesters are looking for the type of hassle-free, low-impact living that a net-zero home delivers.
The first two homes sold at Baird Landing belong to families with young children.
Kelsey Brook architect digs deep, stays green
“I came to realize that what Maine really needed was more energy efficient, comfortable and durable homes,” says Emily Mottram, owner of Mottram Architecture in Yarmouth.
Trained in architecture, she is also a Home Energy Rater, Building Performance Institute Analyst, LEED AP and an Energy Efficient Mortgage Partner. The combination of residential design and home energy performance principles has allowed Mottram to approach home building in a holistic way.
When she first began learning about designing net-zero, super insulated homes, she found that many of them were highly functional but missing aesthetic “curb appeal.”
“It’s not enough to just build something that uses less fossil fuels, it also has to be something that people will actually want to live in and call home.”
Mottram was the architectural firm responsible for designing one of the most recent certified green homes to be built within Freeport’s Kelsey Brook neighborhood. Now nearing completion, Kelsey Brook consists of 15 homes set within 180 acres of protected forests and agricultural land.
Protective covenants about the homes constructed within Kelsey Brook help insure that each is built to the high-quality standards necessary to achieve one of several green building certifications. Eligible programs include the U.S. Green Building Council’s LEED for Homes, Passive House, Net Zero Energy or the ENERGY STAR® program.
It seems that regardless of the green building standards that builders are now following—and homeowners are starting to demand—the notion that simply building a new home that is "up to code" isn’t good enough anymore. That’s a good thing for all of us.
Built for the greener good
Interior of Kelsey Brook's newest home—designed by Mottram Architecture— showing the Tula wood stove that was central to its design. Triple pane windows face west to oer shading from the summer sun and sit just above the floor, giving the appearance of being connected to the woods beyond. Photo: Michael Eric Berube
“More people are wanting to build homes for ‘the greener good’ than they have in the past,” says Matt Senecal, owner of Senecal Construction Services. Senecal built 5 of the 14 homes in Kelsey Brook.
While Senecal and his team partnered with different architects for each home, the methodology used to construct each one remained constant. The basic premise, he says, was to have every member of his crew visualize the finished home standing inverted on its roof—filled with water.
“I wanted everyone on the same page and doing what needed to be done to make sure that every seam in that house could hold water.” His rationale was that a building that could “hold water” would also be air tight, meaning that heat loss through convection (warm air leaking out and/or cold air leaking in during Maine’s cold winter months) would largely be eliminated. Heat loss through radiation and conduction could then be addressed more effectively through insulation and high-performance windows, doors, roofing and exterior sheathing.
This represents a dramatic shift in how homes have been built for the last 100 years here in New England. Building science today no longer encourages homes to be built to “breathe” through constant, unmoderated air leakage. Instead, the mantra is “build tight and ventilate right.”
Flexible design. High performance.
While the debate lingers over exactly how and when local residential building codes are updated and enforced, high-performance home builders are proactively educating their clients about the shortcomings that come with purchasing a home that’s built “up to code.”
“The current building code that builders in Maine are required to follow (IRC 2009) is 6-9 years behind the current technology available today,” explains Bob Muller of Landicity Builders. Muller is the owner and developer of the Douglas Ridge development in Brunswick, a new neighborhood of ultra-efficiency net-zero homes nestled into 280 acres of conservation land.
Over the years, Muller has carefully researched and educated himself on everything from the advantages of communal parking, innovative wastewater treatment (septic) systems that require far less disruption of the existing landscape to install/ operate, as well as different methods of producing high performance homes.
He determined that while traditional modular and pre-fab homes may perform much better than most stick-built (onsite) homes, they often lacked the flexibility of design and style options that he knew homeowners would ask for.
“Through our partnership with Unity Homes, we offer four very distinct styles of homes that will appeal to a much broader range of homebuyers,” says Muller. “From contemporary to classic cape, each Unity Home style can easily be configured inside to accommodate the needs and desires of everyone in the family.” They can also offer custom designs through Unity.
All in, the Douglas Ridge packages range from around $400,000 to $525,000 for a home with 2-4 bedrooms and 2-3.5 baths on a more than half-acre lot, a price he says is just 2-5% more than a stick-built equivalent home that doesn’t have the energy package or smart home tech systems he offers. The energy package, which includes solar panels for electricity, an air exchanger to ensure a steady supply of fresh conditioned air and heat pumps for heating and hot water, means homeowners can expect near zero monthly utility bills well into the future. And that 2-5% premium? You could save that much in energy costs in just a few years.
“How big a hole do you want?”
Muller says that a typical 20-year-old home in Maine might leak at a rate of 15 ACH50 (ACH50 = air changes per minute given an internal air pressure of 50 pascals inside the home). Today, new homes built up to code in Maine are required to achieve air leakage rates of 7 ACH50 or less. According to energy efficiency experts, that’s still a lot of wasted energy (and money).
Muller is among many who believe that homes can—and should—be built to a higher standard.
“Most people don’t understand what a technical building term like ‘A-C-H-Fifty’ really means,” says Muller. “Instead, I’ll ask them ‘How big of a hole do you want?’ Everyone understands that a smaller hole is better.”
“The 2,000 sq. ft Unity Home we raised at Douglas Ridge was assembled on site in five days and is air- and weather-tight,” says Muller. “At the end of the week we did a blower door test that measured at 0.7 air changes per hour (.7 ACH50). That’s incredibly tight—on par with what would be acceptable in a Passive House building.”
Finding Unity and the right time to build
Unity Homes is an innovative New Hampshire firm that has been “scientifically” manufacturing high-performance building panels that deliver long-term durability for decades (prior to 2012, as Bensonwood, Inc). Constructed off site in a state-of-the-art, climate-controlled manufacturing facility, the collection of individual panels arrives at Douglas Ridge carefully crafted, numbered and shipped from Unity to be assembled in a matter of days. Each panel arrives gasketed and sealed to create an airtight envelope that only gets stronger with each finishing step.
The result? Five days to assemble a home shell that will be ten times more energy efficient than a code-built home that might take six months to build. Now that’s something that any barn-raising Yankee can appreciate.
Muller has been patient about moving forward with the development of the land he’s owned for several decades. It is important to him that it be put to good use, creating a cluster of residential housing that becomes part of the existing landscape instead of trying to replace it. Muller remains steadfast in his intent to create a special place where people and families can come together and live in homes that are solid, green, highly efficient, healthy, nature-centric and built to last.
The stars begin to align
As an ever-widening swath of people across the state is exposed to the benefits of energy-efficient living, including lower fuel bills and healthier indoor air quality, it appears the stars are beginning to align in a way that will allow cost, convenience and aesthetic compatibility to coalesce when purchasing a new home.
Additionally, as each new green subdivision is built, it becomes easier for the next project to be completed. More workers become trained in up-to-date skills and more real estate agents become better educated on the benefits of a net-zero home.
The more developers can find, purposefully design, develop and sell properties such as Baird Landing, Douglas Ridge and Kelsey Brook, the more difficult it will be for other developers to build out land in ways that are less concerned with energy efficiency. Perhaps these pioneering efforts will lead to a simpler path for Mainers to plug into a greener lifestyle, one well-designed cul-de-sac at a time.
This article originally appeared in the 2018 fall/winter issue of Green & Healthy Maine HOMES. Subscribe today!