One-of-a-Kind Green Homes

Project #2 - Tied to the Earth

Solar panels on the pool house roof generate power for hot water and about 50 percent of the home’s electrical needs. The butterfly roof collects rainwater. Photos: courtesy of County Timber Frames

This earth-bermed, timber-frame home in Lititz, Pa., earned a LEED Gold rating and would have been LEED Platinum had it been smaller. The clients extensively researched sustainable building methods, and their diligence is reflected in the finished product, says Diener, the builder and architect.

The 3,000-square-foot home is set into a hillside, with the first floor about 8 feet below ground level to utilize the earth as a natural insulator. The 1.4-acre site has an unobstructed southern exposure. Windows are oriented to the south, and solar photovoltaic roof panels on the pool house produce about 50 percent of the electricity needed each month. Two additional solar panels provide electricity to heat water. In the winter, the home’s electric bills average about $100 per month.

Thermal mass is used throughout to absorb sunlight and retain heat. The concrete floors are 6 inches thick, and an 8- to 10-inch-thick, waist-high wall separates the foyer and living area. A 32-inch roof overhang reduces heat gain from windows in the summer. Other features include a geothermal heat pump, a rainwater harvesting system, and permeable paving.

Exposed timbers create a rustic ambience in the kitchen and other living areas.

All of the main living areas are on the first floor, including the master bedroom and den, which the husband uses as a home office. Additional bedrooms on the second floor are reserved for guests. A large storage area was built into the garage.

“The overall footprint of the house was reduced somewhat during the design phase, but the husband really didn’t want to compromise on a lot of things,” says Diener. “He ended up getting about 90 percent of what he wanted.”

The timber framing is both structural and stylish. Exposed rafter tails and other details add character. The stone on the exterior is typical of older homes in the area.

A waist-high concrete wall bordering the family room absorbs sunlight and retains heat during the winter. The flooring is 6-inch-thick concrete.

Deep roof overhangs reduce solar heat gain through the windows, so there’s less need for air conditioning during the summer.