Editor's Note: This is the third in the Summit Daily's Earth Week series, with Earth Day falling on Friday. Thursday, we'll showcase the Governor's Energy Office's Colorado Carbon Fund campaign.

After a year of tracking data, Clark Johnson can prove his home is a net-zero custom home.

From April 2010 to today, utility bills show the family's energy usage in winter is outweighed by the energy produced by the home's photovoltaic array in the summer. After applying standard conversions, Johnson estimates the house put 206 kilowatt hours of energy back on the grid over 12 months.

Whether Johnson's home is the first net-zero custom home in Silverthorne or not, he's not sure, though he's been proclaiming that status for awhile now without opposition.

“A lot of people think (this) doesn't happen very often, and they're right,” he said.

For those interested in how to design and build an energy-neutral custom home — and live the lifestyle required to make the utility bills show it — Johnson is holding an open house today. From 10 a.m. to 2 p.m., the public can stop by 1105 Bald Eagle Road in Silverthorne to talk about the home's features and see it all with their own eyes.

“It's an example of taking it to the extreme of what's possible,” Johnson said, adding that he can provide a unique perspective as both a builder and resident — who charges his electric car off the house system in summer and operates his business, with all its equipment, from home.

“I live in it, so I can tell people what it's like and what I'd do differently next time,” he said, such as having confidence in his systems and not installing as much redundancy between the solar and the boiler.

Heat without the grid

Between solar energy and the masonry heater, the 2,800 square-foot home has hot water and warm air, Johnson said. Though the house has in-floor radiant heat and the boiler is connected to the water system, it's generally in the “off” position. When the water's not hot, generally in winter, the family occasionally switches the boiler on for an hour or so to bring it up to temperature.

The masonry heater stays warm for days, Johnson said, adding that he campaigned for the code change in 2008 to allow them, breaking Silverthorne's mid-1990s solid fuel-burning device ban.

“There's no way we'd be net zero if we didn't have this in our home. It's a great piece of the old world,” Johnson said.

Other sustainable elements

The home's design also employs beetle-kill wood in the furniture, dining room ceiling, trim, doors, siding, recycled wood block walls and more.

Many of the materials come from Colorado, such as the Canyon City stone trucked less than 500 miles. The pallets carrying the wall blocks were deconstructed and installed on the living room ceiling. And the wall blocks, along with insulation and windows, help with the energy-efficient thermal envelope. The blocks provide thermal mass that maintains even temperatures.

The home's orientation is on an east-west axis with broad south-facing windows to maximize passive solar in winter and eaves that block the higher sun in summer.

Appliances — such as the electric induction cooktop that can boil water in several seconds — were chosen based on energy consumption.

Living their life

Johnson said his family's lifestyle hasn't changed much to keep energy consumption to a minimum.

“We're not skimping on showers and baths,” he said, nor are they changing the way they eat or live.

However, the family does take certain sustainability measures — many implemented before they moved into the home.

Johnson didn't install a clothes dryer, for instance, because it's up there with hot water as the highest energy consumer in a house. There's space for one, but the cabinet currently holds cleaning supplies on shelves. Instead, he added retractable hanging racks to air-dry the clean clothes.

The home's greenhouse doesn't necessarily add to its net-zero capabilities other than to reduce some “food miles,” Johnson said. The family grows lettuce, broccoli, tomatoes, berries, citrus, herbs and flowers — they are even trying to raise vegetarian tilapia in a small pond in the greenhouse.

The heating system for the greenhouse is known as a climate battery. It takes air from the ceiling and transports it into pipes underground, keeping the room at about 40 degrees year-round without other heating aside from a space heater on the coldest winter days.

Between the food produced there and what they get from Grant Family Farms, they are leading a more sustainable lifestyle.

“Just because you design and build a net-zero home doesn't mean it's net-zero,” Johnson said. “It's in the lifestyle that the rubber hits the road.”

Takeaway for the layman

It would be tough to get close to net-zero in an existing home without starting from scratch, Johnson said.

However, for a fraction of the cost of a new home, a house can be made exponentially more efficient.

Johnson recommends turning down the hot water a few degrees. Air-drying clothes can save significantly on energy, too.

That hits the big energy consumers, but he also added that caulking windows, woodwork and doors can do wonders.

“When you add up the little cracks in a home, it could be hundreds of feet of cracks ... that you could fit through if it were a hole,” he said. The more technical approach to the same action is a home energy audit.