The finished project abounds with green qualities and universal design features to accommodate old and young, people with disabilities or without. Most prominent are the 54 rooftop solar panels that supply 90 percent of the home's electrical load, the ramp to the front door and the interior elevator that's big enough for a wheelchair.

For most remodelers, one of the most challenging decisions is choosing the right general contractor. For Harrell and Benson, it was the easiest because Harrell is the founder, president and chief executive officer of Harrell Remodeling Design + Build in Mountain View, and Benson is the co-owner.

Founded in 1985, the company employs its own architects, designers, project managers and skilled workers, and also has a list of trusted subcontractors. It specializes in environmentally friendly projects.

The work started in June 2007 and was finished 13 months later. Thus it met another of the couple's goals: It was completed in time for the biennial Peninsula and South Bay home tour sponsored by Build It Green on Sept. 28. Build It Green is a Berkeley nonprofit that rates homes on energy efficiency, resource and water conservation, indoor air quality and other criteria.

Because of the home's energy- and water-saving features as well as materials with low or no VOCs (volatile organic compounds), its use of wood that was recycled or certified by the Forest Stewardship Council, other reused materials and ecofriendly techniques, the home received a high score from Build It Green. Harrell estimated that between 350 and 375 people visited the home during the tour.

In December, the project won three awards from the Silicon Valley chapter of the National Association of the Remodeling Industry: the Platinum Metamorphosis Award in the universal design (barrier-free) category and two Judges' Choice Awards as the greenest and overall best of the 43 projects in the contest.

Harrell declined to say how much the project cost. "We consider it proprietary," she said.

This was the home's second remodeling. The first took place in 1992, when the couple bought the house. The developer had built it in 1986 and used it as an office. Among other work, they tore down walls to create the living room and kitchen upstairs and the master suite downstairs. The kitchen area was converted to a walk-in pantry. The home worked well for many years, but circumstances changed.

Eye-opening experiences

Two years ago, Benson's mother moved from Dallas to a senior facility in San Francisco. She visits the couple frequently, often staying overnight. "We wanted her to be comfortable," Harrell said.

In addition, Harrell's brother had to use a wheelchair for six weeks after foot surgery. The experience was an eye-opener for everyone: Even though he has a single-level house in Reno, he couldn't negotiate the 4-inch riser at the front door until he got a wheelchair ramp. Staying at his sister's two-level house would have been an even greater challenge.

The couple realized that several neighbors had left their two-story houses and moved into single-level homes because of stairs. Benson and Harrell love living where they are and want to stay. As Baby Boomers, "we all think we're still 17," Harrell said, but what about 30 years from now? That's why the principles of universal design - tailored to meet the needs of people of all ages and abilities - were so important.

The couple also wanted to update the kitchen and expand the lower level of the hillside house, and they wanted a home that Harrell could easily show to potential clients.

"People have these predispositions about what green is," Harrell said, adding that they don't think a house can be both green and beautiful. With its handsome materials and clean, uncluttered design, her home erases such preconceptions.

The couple selected two people from Harrell's staff to run the project. Genie Nowicki did the design, and Neil Schultz was site manager. Besides doing some specialty carpentry, he managed the subcontractors, set up schedules, approved the bills and met weekly with Nowicki and the homeowners, just as he would on any other job.

Before construction began, Harrell and Benson moved from the master suite downstairs into the guest room upstairs. Like most people, they had accumulated lots of possessions over the years, so they hired an organizer to help them decide what to use upstairs, what to store and what to discard, preferably by donating it to charity.

They also prepared a furniture plan so they'd know what to keep or replace. Some items were sent off for refinishing or reupholstering.

"The process is very cleansing emotionally and spiritually," Harrell said.

Living upstairs worked for a while, but then the workers needed access there, so the couple rented a house from December through May. The upstairs wasn't finished when they returned, but the new laundry-storage area downstairs had a sink, dishwasher and microwave that suited their needs temporarily.

"Now I know why I always advise clients to move out during a remodeling project," Harrell said. She believes that two months could have been shaved off the project if the home had been unoccupied the entire time.

Once the work started, everything downstairs was stripped to the studs. Doors were moved. Windows were added for natural light and ventilation. A concrete pad was poured for an elevator, which opens on one side upstairs and on the other side downstairs. The elevator also required building a shaft and installing mechanical equipment on the roof.

The crawl space, which had been used for the laundry and a closet, was excavated by hand to avoid disturbing tree roots (a conveyor belt carried the dirt to the street). For the same reason, concrete for the new floor was delivered by hose, a one-month process.

Excavating and finishing the crawl space added about 300 square feet to the roughly 4,000-square-foot home.

Exterior walls downstairs were sprayed with Icynene, a rigid foam insulating material. Batts of insulation made from denim scraps were used on interior walls to reduce noise. Some of the old insulation from downstairs was used on the new walls upstairs rather than winding up in the dump.

"We did a lot of repurposing," Harrell said, adding that a deconstruction specialist separated recyclable or reusable materials from trash to minimize trips to the dump.

For example, the sink and dishwasher in the expanded laundry-storage room came from the old kitchen. Window blinds from upstairs now close off luggage storage shelves along one wall of the laundry room.

The couple gave site manager Schultz the hot tub that was in the master bathroom and replaced it with a sauna. A Berber carpet from elsewhere in the home now covers the floor in the expanded master closet.

The surface of the island in the laundry area is heated to reduce humidity. The couple prefer line-drying their laundry, except for sheets and towels, which go into the dryer.

Ventilated shoe closets

The new, L-shape master closet connects the laundry area with the master suite and features such niceties as ventilated shoe closets and enclosed niches for jewelry.

Like the two other bathrooms, the master bath has a heated floor and curbless shower for easy access. It also has a hydronically heated towel rack and shower seat.

Completing the master suite are the bedroom, the den with entertainment center and Harrell's office, each with a gas fireplace. A sliding door with a stained-glass window is suspended from overhead in the den to close off the stairway, thus increasing privacy and preventing heat loss to the upstairs.

The upper level has decks on three sides. With views of the hills, the living room dominates this level. Although it's all one space, it's defined by three glass panels etched with quilting patterns, suspended from the ceiling and back lighted.

Besides defining the space, the panels add light, visually lower the 14-foot-tall ceiling and reflect Benson's interest in quilting. She designed the center panel; the two others are traditional quilting designs.

Because both women like to cook, the kitchen has two work areas. The center island features a cooktop plus a heated counter so that hot pots and dishes stay warm. Adjoining the kitchen are a sitting area with gas fireplace and the dining area. Also upstairs are Benson's office, her quilting studio and a guest bathroom with an adjustable-height counter. A queen-size Murphy bed converts Benson's office into a guest room, as does the twin-size Murphy bed in her adjacent quilting studio.

Pocket doors are used wherever possible to create a more spacious feeling. Vertical slats are added to closet doors in hallways to allow the visually impaired to distinguish them from other doors.

Other features include programmable light switches, an intercom system, remote-controlled rolling shutters for the living room windows and a 75-gallon water heater with a programmable timer to turn it on for three hours in the morning and again in the evening.

The yard of the third-of-an-acre property is landscaped with native plants and a drip-irrigation system.

The project lost some Build It Green points because it kept the original furnace and air conditioner, but "the whole point (of the improvements) was not to use the air conditioner," Harrell said. Installing five gas fireplaces helped, too, because these appliances serve as space heaters, reducing the load on the furnace.

Herrell's last bit of advice: Remember that "it's a long dance. Celebrate your successes along the way."

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This article appeared on page F - 1 of the San Francisco Chronicle