Blog

 

The timber frame structure, often associated with traditional barns from the 19th century and earlier, makes a wonderful structure for modern design. Two of our recent projects incorporate a timber frame to achieve striking results.

 

hybridhouse

 

hybridhouse: On the shore of Bare Hill Pond in Harvard, MA, our client requested an intimate house that reflected their love of modernism. A cutting edge aesthetic is achieved with a flat roof, dramatic overhangs and a wall of glass facing the water.  A wood structure of glue-laminated timber frames the large windows facing the water. The back of the house, facing away from the water is framed with standard insulated 2x4 walls resulting in an effective hybrid home.

 

 

woodshop

 

woodshop: Our client owns a beautiful wooded property on Hickory Island where the St. Lawrence River meets Lake Ontario. The stand of white pines where the barn and future home are to be built provide the timber resource.  Working with New Energy Works, a local timber frame company, Flavin Architects designed the barn with a modern interpretation of the gable form. In contrast to traditional New England barns, where the timber frame is concealed from view by the exterior cladding, we pushed to celebrate the building frame, exposing it on the inside and the highlighting the mass and beauty on the outside.

 

New Energy Works Website: http://timberframe-postandbeamhomes.com/

 

Timber Framing uses large squared off wooden timbers, widely spaced to create the building’s frame. The inherent systems ability to span large distances made it common to use as a barns structure where flexible open interior space is ideal. Traditionally, the timbers are joined with intricate connections requiring exquisite craftsmanship. We now employ easier to install steel fasteners that are far more rigid than the traditional joints.

 

Advantages of modern timber framing:

 

·         You See What You Pay For: In conventional homes, standard wood framing relies on many smaller members in the 2” to 10” range, which are hidden from view with interior drywall and exterior sheathing. Our timber frame projects use fewer larger members in the 6” to 12” range. The exposed framing becomes integral to the beauty of the structure. The higher cost of timber framing can offset the need for elaborate interior embellishments of trim. For modest additional cost, the framing can be upgraded from pine to finished grades of douglas fir and other attractive types of wood.

 

·         Reduced use of Wood: While larger members are used, they are more widely spaced than traditional framing, reducing wood used by about 20%. In addition, the large “natural timbers” can be replaced with glue-laminated timber frames.

 

·         Insulating: While timber framing is ideally suited to un-insulated utility buildings, for houses, insulation needs to be approached differently, if the timber framing is to remain visible. Rigid insulation can be applied on the exterior preserving the timber frame on the interior.

Spray Foam insulation has been specified by our office for both residential and commercial projects with successful results. Although cost is always a concern, we prefer spray foam insulation over standard fiberglass batt insulation because of its comprehensive insulating and air sealing capabilities, along with a proven long term durability record.

 

 

What is Spray Foam insulation?

Foam insulation is a polyurethane that is sprayed into the wall and ceiling cavities, which expands and cures within minutes. As it expands in the cavity, it fills all of the voids and crevices, creating a continuous air barrier. This air barrier substantially reduces the outside/inside air movement, which historically results in tremendous heat loss and water vapor movement. Spray foam insulation can be specified in two ways; open cell or closed cell, depending on final desired performance capabilities required. Open cell insulation has an R-Value of 4/inch and allows a small amount of vapor movement, while closed cell insulation has an R-Value of 7/inch and allows less than 1.0 perm of vapor movement, which classifies it a Class II vapor retardant. Many of the spray foam insulation products in the marketplace are Energy Star Certified. Spray foam is sold under brand names such as Icynene, Certainteed, and Corbond.

 

Why Spray Foam insulation? There are several advantages to installing spray foam insulation:

  • Reduced Energy Use:Spray foam has an air sealing capability that allows furnaces and air conditioners to run more efficiently, instead of having to adjust based upon typical building envelope air leakage. With as much as 30% of house air leakage being directly attributed to poorly sealed and insulated walls, floors, and ceilings, the installation of foam insulation has the potential to reduce heating and cooling energy costs. And because the foam serves as an effective air barrier, incorporating a well designed ventilation system that facilitates sufficient fresh air movement is a critical consideration, which can be achieved by an engineered mechanical system with adequate fresh air intakes.
  • Better Indoor Air Quality:Spray foam insulation will minimize the infiltration of airborne irritants such as allergens, drafts, or humidity. Tests have proven that spray foam insulation is not a food source for mold.
  • Moisture Control:99% of moisture in your home is born from air infiltration. In order to manage moisture in a home, the air flow must be minimized. Once spayed into the cavity, the foam adheres to the structure and expands into hard to reach areas, such as around electrical outlets and ceiling lights. We typically specify closed cell foam in the ceiling cavities, which eliminates the need of venting attic and rafter bays, keeping all potential condensate out of the roof/attic.
  • Sound Control:As result of the thousands of microscopic air cavities,spray foam insulation has substantial acoustical attenuation properties, effectively reduce the amount of noise from plumbing lines, general room to room ambient noise, and from exterior to interior.
  • Durability:Spray foam Insulation is flexible and will move with the building’s natural shifts over time. And unlike Batt insulation, foam will not settle or sag once it is place, which results in a wall or ceiling assembly that has a consistent R-value.

Cost Analysis:

Spray foam insulation cost, including installation varies from $4/sqft for open cell to $7/sqft for closed cell. Standard Fiberglass Batt insulation including installation costs an average of $1/ sqft. In a typical 2,500 sqft home, insulating the roof and the exterior walls, the total is insulate would be approximately 6,400 sqft. The cost to insulate with Batt insulation would be $6,400. To install a hybrid spray foam assembly, with Open cell foam in the exterior walls, and Closed cell in the roof framing, the total cost is $34,632. To install Closed cell throughout, the total cost would be $44,832. Combined with the previously mentioned energy savings and air sealing capabilities, many of our clients find the upfront added cost for spray foam reasonable when considering all of the added value and benefits.

Our client’s 1960’s house, originally conceived for summer use only, was in need of a major upgrade and expansion to accommodate year-round living.  The site’s beauty and location, perched within a stone’s throw of a beautiful salt water marsh in coastal New England, posed many planning challenges, including proximity to coastal wetlands and coastal flooding regulations. Added to the site planning mix was the clients request we minimize energy use with a geothermal system.

 

coastal geothermal

 

What is Geothermal: Geothermal, also known as a ground source heat pump, uses the earth’s constant 55 degree temperature to provide much of the heating and cooling energy for a home. Working with Sean Fennessey of Sun Engineering, a closed loop system was specified, where four 350’ deep bore holes are located on the property, providing a below-grade closed loop assembly to be used efficiently by a series of water to air geothermal heat pumps.

 

Why Geothermal? There are several advantages to a geothermal system:

  • Reduced Energy Use: In conventional homes located in New England, when heating is provided by oil and cooling is provided by electrical outdoor condensers, an annual average of 92 million BTUs from oil and 1600 KWH of electricity are consumed. Since a geothermal system has a number of parts and motors, the electric consumption is reduced very little, but by removing the demand for oil, approximately 850 gallons are saved, for a total cost savings of approximately $3,500/year.
  • Reduced Cost: The high initial cost of a geothermal system is offset by both a 30% Federal tax credit and a $1,750 Rhode Island tax credit, applicable to not only the required geothermal parts and install, but the entire heating/cooling assembly, including ducts, diffusers, hangers, etc. For this project, the total cost of the HVAC system has a 66% additional cost over a conventional high-end system. However, this is reduced by the State and Federal Tax Credits, for a net increase of only 14% for a geothermal system. A home of this size with a conventional HVAC system is expected to consume 1,700 gallons of oil annually, costing $6,000 at today’s energy prices. The geothermal system is estimated to save the client an average of $4,000 per year, paying back the original investment in approximately 3 years, along with peace of mind.
  • More Beauty! Conventional home cooling systems require several exterior condensers, unsightly boxes that are also noisy and occupy valuable land. Geothermal eliminates the need for the exterior condensers and pads, replacing them all with the above-mentioned internal heat pumps, located in the building’s available basement.

System Particulars: The engineered design called for a well field, composed of four 350’ deep bore holes, located outside of the adjacent sensitive wetlands. A closed-loop 1 ¼” plastic pipe, surrounded by high conductivity grout, circulates a safe, food-grade glycol/water mixture, and is connected to a heat exchanger. The geothermal interfaces with conventional efficient water to air heat pumps, where a balance of fresh and inside air is circulated over the hot water coils in the winter and cold water coils in the summer. Along with comprehensive humidification, a state-of-the-art air filtration system, and constant outside air supply, this is available technology that has an extensive performance history and adds value to the home investment.

Pages