At our monthly meeting on October 21, we enjoyed a presentation by Mark Whalen and Randall Elgin on building a “green” home. Bringing their own story of building (and learning as they went) a home they gave the details not only of construction and benefits, but what to expect from building inspectors, banks and builders.
People with a specialized interest in this type of project are critical. Some architects are now investigating this technology to use in their designs. There is a “sub-culture” of builders who specialize in this area.
“Green” low energy homes have been around for many years and interest in building this way has resurfaced in recent years.
This type of home is predominantly heated passively by the sun, and uses tight, heavily insulated construction. The location on the lot and placement of windows are important factors in the home’s design. Large windows facing south collect the sun’s rays, heating a concrete floor which, because of its density acts as a storage bank for the heat collected. You may think “Concrete? That must be ugly!”, but there are many attractive finishes for this material, including the look of fine tile.
The insulation used in the home exceeds the requirements on the Massachusetts Building Code by two to three times. The foundation and interior wall are made of concrete sandwiched between non-flammable plastic foam panels. The concrete (again because of its density) acts as a temperature buffer between the inside and outside, so less heat and cold are exchanged in the different seasons. The roof is made of a 12” foam block sandwiched inside twenty foot by eight foot wood composite panels attached to 2×12’s every four feet. Because this is so rigid, inside supports (beams) are not required and a wide open cathedral ceiling can be used.
For auxiliary heat, a small (looks to be smaller than a clothes dryer) gas fired boiler heats a radiant hot water floor system at ninety-eight percent efficiency.
Because the house is so “airtight” a Heat Recovery Ventilator was installed to bring fresh outside air into the home, while reusing the heat from the inside air.
Even the “gravel” driveway is made of crushed recycled materials.
The house can be finished and painted inside and out just like a conventional house, and the plastic foam is difficult if not impossible for insects to damage.
Relative to standard construction this type of home uses only forty-two percent of comparable energy.
Mark can be contacted by email at mark.e.whalen@lmco.com