This week: Eco-friendly homes

1 Hubbardston, Mass. This 2004 four-bedroom home gets electricity from its own solar energy system and heat from a geothermal multizone hydronic system. The open-plan house has high ceilings, a granite fireplace, two sunrooms, and a gourmet kitchen with floorto-ceiling custom cabinets. The 15.65-acre property includes fields, gardens, a subterranean greenhouse, an outdoor shower and hot tub, a two-story garage, and a blueberry patch with a 60-pound annual yield. $1,550,000. Linda Bourgeois, Coldwell Banker Realty, (978) 340-5424

4 Napa, Calif. This passive-solar circular home by architect Craig Henritzy is built with energy-efficient Rastra Block. The three-bedroom house, influenced by Frank Lloyd Wright, features reclaimed teak and natural stone, an open-flame fireplace, and a sunken-amphitheater living room. The 7.75-acre wooded property has walled stone patios and pathways, a fountainwall entrance, and views of San Francisco Bay and Mount Tamalpais. $5,000,000. Sieba Peterson, Golden Gate Sotheby’s International Realty, (707) 932-1276