Green Valley Builders welcomed a group of Virginia Tech students to a build site where all homes will be EarthCraft and Energy STAR certified, allowing them to see first-hand energy efficient building strategies in Blacksburg. Here is a press release and photos from Green Valley Builders:

On April 20, 2010, Justin Boyle of Green Valley Builders hosted a group of undergraduate and
graduate architecture students at the site of a new home in the Mount Tabor Meadows
community in Blacksburg. The home visited is part of a 49-lot development in which all homes
will be both EarthCraft and ENERGY STAR certified.

The students visited the site as part of Assistant Professor Elizabeth Grant’s Environmental
Building Systems and Architectural Systems Integration courses, part of the curriculum of the
School of Architecture + Design in the College of Architecture and Urban Studies. During the
tour, Justin Boyle explained that while many ancillary systems such as photovoltaic arrays and
solar thermal domestic hot water are popular methods to reduce reliance on traditional energy
sources, making a building energy-efficient begins with the basics. These, according to Boyle,
are framing the house to reduce thermal bridging, providing sufficient insulation to slow heat
flow through the building envelope, and installing energy-efficient heating, ventilation, and air
conditioning systems. Boyle pointed out several examples of each of the these strategies, from
the “California corners” and ladder tees used to frame exterior walls, to the low-density foam
and cellulose insulation located in wall and ceiling cavities, to the ductwork sealed with mastic
located entirely within the thermal envelope of the house. Among other benefits, constructing
houses in this manner has allowed Green Valley Builders to install much smaller heat pump
units in their houses compared to the industry norm. The house toured has a 2.5 ton heat pump
designed to serve 4,000 square feet of conditioned space; with standard construction a house of
this size might call for a unit with three to four times more capacity.

In addition to these building techniques, houses at Mount Tabor Meadows include energy-saving
features such as an energy recovery ventilator that pre-conditions incoming makeup air
using air exhausted from the home. This device improves indoor air quality while reducing
energy loss. The house featured on the student tour also has provision for a 2KW photovoltaic
array, a solar thermal domestic hot water system, and a grey water reuse system to be installed
by the owner at a future date. Other homes in the community currently take advantage of these
systems, and one home is anticipated to be the first LEED for Homes certified building in
Blacksburg.

The participating students and faculty appreciated the opportunity to see this demonstration of
energy efficient strategies and good building practices at the residential scale in their own
community.