Boulder, Colorado. Lion Point is a six-bedroom home with a green roof using both passive solar design and solar panels. Floor-to-ceiling glass walls slide open to multiple balconies; among other features are hickory floors, a chef's kitchen with Colorado marble, and smart-home technology.
The 15-acre canyon property includes a two-bedroom guesthouse. $3,950,000. Chip Bruss, LIV Sotheby's International Realty, (303) 638-8242.
Kailua-Kona, Hawaii. Set on a half-acre landscaped lot on the Big Island, this 28-panel, three-bedroom house looks out on the Pacific Ocean. The open-concept home features cherry floors, ipe inlay work, bronze hardware, a kitchen with etched-glass cabinets, and a master bedroom with a private patio and sunset views.
A roofed porch wraps the house. $1,150,000. Carrie Nicholson, Hawaii Life Real Estate Brokers, (808) 896-9749.
Denison, Texas. Built in 1984, this 3,035-square-foot, three-bedroom concrete-and-granite house uses 80 solar panels, a geothermal system, and a reverse-osmosis water filtration system. Architectural details include stone floors, crown moldings, wood trim and cabinetry, and a flagstone fireplace.
The 32-acre property features a patio area, a small pond, and a detached office. $3,000,000. Terrin Bertholf, Easy Life Realty/Gunter, (903) 267-1573.
Ketchum, Idaho. This three-bedroom 2015 home was designed with rooftop solar panels. Inside are a chef's kitchen, great room, multiple fireplaces, wine storage, and a full-floor upstairs master suite with a private deck.
Oversize windows open to a second large deck with views of Bald Mountain. The Sun Valley Resort bus stops out front for a five-minute drive to the lift. $2,300,000. Katherine Rixon & Rob Cronin, Keller Williams/Sun Valley, (208) 622-7722.
West Orange, New Jersey. This five-bedroom home near New York City was built in 1954 and recently extensively renovated. The house has radiant-heat floors, high ceilings with skylights, a European kitchen, two fireplaces, a master suite with a soaking tub, and a lower level with a family room and a gym.
The 2-acre property includes a large patio, a play area, a pool, and a hot tub. $1,496,000. Amy Roy, Halstead Property, (201) 478-6736.
Patagonia, Arizona. Situated on 46 acres of open range, this off-the-grid home has a photovoltaic system and a wind-and-solar-pumped well. The two-bedroom earth-sheltered house, inspired by the designs of Arcosanti founder Paolo Soleri, uses many Soleri signatures, including freeform curves and colored glass.
The naturally landscaped property features a one-bedroom guesthouse and views of Red Mountain. $359,000. Mary Vincent, Tierra Antigua Realty, (520) 255-3068.