EcoHome checks in with Amy Cornelius, general manager for West Grove, Pa.-based Hugh Lofting Timber Framing.
Credit: Rick Ziesing
The company’s LEED-Silver home in Kennett Square, Pa., boasts an insulated precast foundation, SIPs construction, passive solar design, and sustainable timber framing.
How long have you been in the building business?
Hugh Lofting Timber Framing has been in business for 36 years.
When did you first become interested in green building? Why?
In 2006 we were asked to provide the timber-frame structures for an exhibit at the Philadelphia Zoo. The architects, who were from California, specified “environmentally aware pressure treatment” for the timbers, something that we had never heard of.
Through the research on this project we learned a lot about green building, the USGBC’s efforts, carbon measurement, etc., and realized that the company’s philosophy had always been to build green but that it had never been formalized in marketing or training. After that I achieved LEED-AP status and the company began to tell the story of its green efforts through the years.
What is your overall philosophy/approach to green building?
We work with clients from design inception to create beautiful, energy-efficient homes and buildings that are easy to operate and easy to live in. We use FSC-certified timbers and glued-laminated beams, reclaimed and salvaged woods, low-VOC finishes, and structural insulated panels.
We adhere to an integrated project management approach to design and construction: First, we study the site and building orientation; second, we use a systems approach to achieve high R-values and tight construction; and third, we rely on earth-based HVAC systems, including solar thermal, PV, and geothermal, with conventional HVAC technologies last.
For example, in the LEED-Silver home we recently built we used a precast foundation from Superior Wall, an off-site-built timber frame, and precut structural insulated panels. This series of systems reduces site waste (no lumber cut-offs, concrete wash-out or overage, insulation debris), allows tighter tolerances (fully engineered drawings developed pre-construction and factory built for increased quality control), and reduces construction time because it’s pre-assembled.
In 2009, Hugh Lofting Timber Framing became a B Corporation to align ourselves with other companies who are succeeding and doing good; we feel that the two are not mutually exclusive. We are committed to a triple–bottom-line approach to measuring performance in terms of our impact on the community, our impact on the environment, and our profit that underlies the B Corporation mission and we want to support the movement’s growth in the business community.
What is the current state of the timber framing industry?
The traditional definition of timber framing--a frame constructed of heavy timbers using mortise-and-tenon joinery that is held together with wooden pegs--is expanding as the industry and design aesthetics evolve. Designers’ desires for longer spans and more complex joinery coupled with increased engineering review rigor is driving timber framers to include more steel in their projects and to use a multitude of metal fastening systems. This steel can be hidden within the frame or it can be visible or expressed. Most often expressed steel is seen as an integral part of the overall design of the structure.
Many timber framers are also working with manufactured timbers including glue-laminated and PSL (parallel-strand lumber) material. These timbers, manufactured from thin pieces or “slices” of kiln-dried wood and then adhered with adhesive under pressure, have high tensile strength and allow designers to achieve significant spans. They can also be quite beautiful.
Why is timber framing considered sustainable?
It all starts with the wood, a natural, non-toxic, biodegradable, and renewable material that is a natural carbon sink. Often timber frames are cut by hand or with minimal input from small machines and are usually crafted and prefit in the shop. This results in a low-embodied-energy product, a reduction in project construction time, increased quality control, and a reduction in construction waste. Timber frames are durable and have long life spans; there are some that are more than 2,000 years old!
One way to ensure the timbers we use are coming from sustainably managed forests is to specify that timbers come from Forest Stewardship Council (FSC)-certified sources, standing dead or forest salvaged sources, or local family farms, or are reclaimed from local barns and warehouses. When working toward LEED certification, it is important to specify FSC timbers in purchase orders and to get proof in the form of chain-of-custody documentation and on the invoice from the vendor.
Once the frame has been raised, it can be enclosed with many different strategies, but many timber framers use structural insulated panels, which provide a high R-value and reduce air infiltration and heat loss.
Why are upfront planning and collaboration important when building a green home?
Using an integrated project management approach right from the start of the design process brings all of the team together to share ideas, air and discuss problems, and identify solutions. This team can include many disparate roles, including the owner, the general contractor, project neighbors, future project occupants, the electrician, the plumber, the HVAC contractor, engineers, building inspectors, and township officials.
By bringing the team together early, synergies between systems can be developed that might not be apparent if they were designed independently. For example, on a zero-energy home near Annapolis, Md., we are currently working on, energy modeling indicated the need for a 3-ton heat pump to meet backup heat and air conditioning issues. But as a result of the design charrette process, the home underwent a dramatic redesign that changed the HVAC system design entirely to be more passively based, reducing the heat pump to 2 tons and reducing the house size by more than 1,000 square feet.
What is Green Advantage and what does it mean to be certified?
The Green Advantage program provides green building education for commercial and residential construction practitioners. The program uses the framework of the LEED for Homes and LEED for New Construction certification systems as a base for its instruction. The training covers all aspects of the planning, design, and construction process providing a thorough introduction to green building best practices. Our entire staff is Green Advantage trained.
What is the market like for green residential building in your area of the country?
The green residential market is growing at a rapid pace in our area. Through continued outreach and education I think that it will grow even more.