Originally published in The Weekly Packet, August 14, 2014
Local builder discusses using local materials, timber frame construction
Traditional wood joinery is featured in the designs of builder Jim Bannon, who gave a presentation on timber frame house construction on July 24 at the Blue Hill Library.
by Tevlin Schuetz
Builder Jim Bannon gave a presentation on timber frame construction at the Blue Hill Library on the evening of July 24. He described the process involved in creating a timber frame house and explained why it is a cost-effective and environmentally responsible means of homebuilding.
Bannon owns a business in Blue Hill, called Village Timber Frames, specializing in timber frame home construction, which relies on traditional methods of wood joinery.
Unlike modern home building—in which the skeletal structure of the house is joined together with metal fasteners and is usually hidden inside walls, under floors or above ceilings—timber frame construction employs hand-hewn joints at connection points to support the load-bearing framework. Bannon engineers buildings in which the wood joinery is central to the design and remains in view. This allows for dramatic aesthetic possibilities, Bannon said. The mortise and tenon joints become the primary focal points along with the natural characteristics of the wood and the shapes of the timbers used.
Bannon became interested in traditional wood joinery over 20 years ago and has been building timber frames professionally for the past 12 years. His focus has been on “rethinking the ways in which buildings relate to local ecology,” considering the construction process, materials used and life span of buildings, he said.
In his presentation, Bannon outlined 11 principles to which he adheres when planning and executing construction of buildings, the first of which concerns the lifespan of the structure. He stated that in America the accepted life expectancy of a home is 60 to 100 years per current building and mortgage industry standards, but he noted that in Europe there are buildings that are older than 500 years. He posed the question: “Why do we create buildings that are short-lived when the technology has existed [for centuries] to make houses that last for 500 years?”
Bannon identified three elements that contribute to the structural longevity of his buildings: using a timber frame structure; keeping the sill or base of a home 18 to 24 inches off the ground; and constructing wide roof overhangs, which keep all but the most torrential rains from reaching windows, doors and other components vulnerable to moisture, he said.
The use of local, natural materials such as wood, earth and stone also has several benefits, according to Bannon. For one, they are readily available in Maine and are non-toxic. They also lend their natural beauty to a building and augment the aesthetic of craftsmanship employed in their use.
Bannon also said that using local materials allows a builder or homeowner to bolster local labor, skills and creativity, and contributes to the immediate community rather than the global industrialized economic paradigm. Plus, there is a lot of enthusiasm for the work. “It’s a craft….People take pride in their work,” versus just nailing together 2 x 4s, Bannon said.
Timber frames are easier to maintain and modify with traditional skills and tools, Bannon explained. “Working in a tradition that is old means…we can easily repair old buildings made in the same traditions and with the same techniques.” This ends up being more cost effective overall, and homes which are better-constructed lower demands on forests for their upkeep.
The sourcing of locally available natural materials yields little pollution—if any, if they are found on-site—Bannon said, whereas the creation of synthetic building components and their transport over long distances require significant fossil fuel use.
Bannon gave rough figures on global CO2 emissions, saying that around 47 percent of greenhouse gases come from processes involved in making buildings, and another 25 percent results from transportation.
Bannon’s chief concern is creating homes that are energy-efficient in both their construction and function. Passive solar energy capabilities are featured in his designs, which employ window placement to maximize sunlight exposure and earthen floors to trap heat.
Earthen floors absorb heat during daylight hours and release it slowly at night. They are softer than concrete and thus healthier for people to stand upon with respect to their knees and joints, Bannon said. A member of the 20 person audience asked Bannon about the earthen floor’s resistance to impact, and Bannon compared the strength of the floor to a pine wood floor, stating that they are compacted and sealed with natural oils.
“Reducing heating costs is the biggest challenge,” Bannon stated. Passive solar heating combined with the efficient use of insulation, such as dense-packed cellulose made from recycled newspaper, is effective.
And a building’s roof is key. The challenge is to find natural materials that are durable enough to protect a home for a long time, Bannon said. He identified slate as a would-be ideal roofing material, except that it is mined—which requires high energy use and fossil fuels—and is in limited supply. “Roofing is the problem to be solved in green building. Whoever invents the perfect roofing deserves a Nobel prize.”
Synthetic materials like vinyl siding and rubber faux slate are bad ecological choices, Bannon said. When asked about vinyl siding, Bannon chuckled. “My only experience with vinyl siding is taking it off. I would never use it.”