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Case Study: McCalmont Residence

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The founders of a solar power company find out what it takes to modernize an older home and make it independent of fossil fuels.

“One of our goals was that no fossil fuels be required to sustain and operate the house after the remodeling was finished. It’s a surprisingly hard goal to achieve.” —Tom McCalmont

Project Stats

Location:	Palo Alto, CA
GreenPoint Rated score:	122
Year built	1951
Original size:	3,162 square feet
New size:	3,723 square feet
Project scope:	Whole-house remodel to modernize systems and spaces and create a home that is independent of fossil fuels.
Architect/Builder:	Peter Lyon General Contractor,Inc.
Interior design:	Vision Design
GreenPoint Rater:	Kevin Beck

A Solar Home That’s Ahead of the Curve


	Before construction, front of home.

As co-founders of Regrid Power, a company that installs solar power systems in Northern California, Tom and Darlene McCalmont have a professional commitment to doing the right thing. That commitment carried over into their home lives when they set out to renovate their house in Palo Alto.

Originally a small bungalow with two bedrooms and one bathroom, the house had been added onto over the years but needed extensive updating. “All the systems were pretty well shot,” said Tom McCalmont. “It needed new electrical, plumbing, sewer. But we liked the karma of the house.”
It had belonged to an old family friend who lived there for five decades, and the McCalmonts had many fond memories of times spent there. “I had a lot of connections to the house,” McCalmont said.

Bringing the house up to date was a major undertaking that included seismic retrofitting of the foundation, gutting the house and expanding most of the spaces, installing new insulation, windows and finishes throughout, and replacing mechanical, electrical and plumbing systems. And, not surprisingly, a large photovoltaic system was installed to generate electricity on site.


	SolaTube letting light in through roof.

The McCalmonts were determined to make their home a showcase of what’s possible when it comes to green remodeling. While the end result is a beautiful home that will likely produce as much energy as it consumes, the process was frustrating at times. “There’s a lot of press about green but a lot of it is not very real,” McCalmont said.
When the architect and builder they first hired turned out to have limited experience with green building, the McCalmonts brought on board a team better suited to the project: Peter Lyon and Mark Walter with Peter Lyon General Contractor, Inc. and Sue Harrison and Heidi Lane of Vision Design. “Peter and Mark were very good,” said McCalmont. “Peter said he’s green and he is. He and Mark care about it. We were much more simpatico with them.”

Vision Design, in addition to designing the interiors, played a key role in recommending energy-saving systems and products such as heat recovery ventilation and closed-cell spray foam insulation, and identifying subcontractors to install them.

GreenPoint Rated Adds Value

GPR Certificate Lyon credits Sue Harrison of Vision Design for getting them hooked into the GreenPoint Rated process. The McCalmonts agreed that having the home GreenPoint Rated was a good idea. “It’s not so much that we cared about the score,” McCalmont said. “It was just because of our commitment to green that we thought, let’s do it.”

“It’s an excellent example of everything people can do to make an existing building a building of the future,” said Harrison, who is a Certified Green Building Professional.

For Harrison, one of the keys to improving the performance of an existing home is understanding how its components and systems are interrelated. A decision about one aspect of a remodeling project can have major repercussions—positive or negative—on many other aspects of the building’s performance. She points to her recommendation to insulate the McCalmonts' home with spray foam as an example of the integrated design approach she brings to her projects.

Although “more expensive to install, it is so far superior to pink fiberglass,” she said. “It does many different things. It insulates, it adds rigidity, it eliminates all air and moisture entering the house.”
Spending more on good insulation meant that the McCalmonts could forgo the large and expensive heating systems they had been considering, and opt instead for a comparatively inexpensive heat pump that provides heating and cooling. “The net cost was far less than previously planned,” Harrison said.

“People should see this,” she said. “It’s the perfect example of the remodel of the future.”

Energy Use and Greenhouse Gas Emissions

The McCalmonts took a multi-pronged approach to reducing their home’s carbon footprint: in addition to making it energy efficient, they installed only electric equipment and appliances so that 100 percent of the home’s power could come from the large solar electric system they put in. “One of our goals was that no fossil fuels be required to sustain and operate the house after the remodeling was finished. It’s a surprisingly hard goal to achieve. Most houses use some natural gas,” McCalmont said.


	Click photos for larger view.

No matter how large a photovoltaic system is installed, homes must still comply with Title 24, the state’s building energy efficiency code. The energy code encourages homeowners and builders to make energy efficient choices, such as heating water with gas instead of electricity. But the McCalmonts were determined to go all-electric so that they could meet all their energy needs with a PV system.

“In the end,” said McCalmont, “what happened was we had so many credits on the energy efficiency side—foam insulation, low-e windows, a lot of LED lighting—that it could offset the electric water heater” penalties in the Title 24 code compliance calculations.


	Click photos for larger view.

Insulating the entire building envelope—floors, walls and roof deck—with closed-cell spray foam insulation was just one of many energy efficiency strategies.

The home’s lighting design is “way ahead of the curve,” said Lyon. “Less than 20 percent of the lighting is standard incandescents.” Energy-efficient LED lighting was used extensively throughout the home, including in all the recessed cans, and for the cabinet and accent lighting.

Passive solar design was incorporated into a new south-facing hallway that has a large bank of windows and a slate floor. In the summer, an overhang shades the hallway from direct sun. The rest of the year, when the sun is at a lower angle, the slate floors absorb the sun’s heat. Excess warm air is “chimneyed up to the air return,” said production manager Mark Walter. “All that heat gain in the winter is sent to the HVAC system,” which means the heating system won’t have to run as much.

As part of their quest to reduce fossil fuel consumption, they also wired the garage for electric vehicles. Tom McCalmont drives a retrofitted plug-in hybrid Toyota Prius, and Darlene McCalmont plans to buy an electric vehicle in the future.

The McCalmonts need to be in the house for at least a year before they will know whether their photovoltaic system completely offsets their electricity use. “Even with an 8 kilowatt PV system, we may not be able to make all the electricity we use,” McCalmont said, “but I think it will be extremely good.”

Indoor Air Quality

The home’s heating and air conditioning system includes heat recovery ventilation, which is
programmed to automatically circulate fresh air at a low level on a continual basis.

Skylights for added ventilation

“It’s totally silent,” Lyon said, “and it keeps the house really fresh.”

The back of the house has a 16-foot wide section of accordion doors that can be pushed open to naturally ventilate the house on mild days. When it’s too warm inside, several operable skylights provide a thermal stack effect, drawing warm air up and out of the house.

To reduce indoor air pollution, zero VOC paints and water-based clear finishes were used throughout the home.

Resource Conservation

Although the house was gutted, usable materials didn’t go to waste. “The Reuse People came in and deconstructed it,” Walter said. “They took all the interior doors, windows, cabinetry, and some hardwood floors.”



	Click photos for larger view.

Deconstruction still isn’t common practice in the remodeling industry. “We drive around the neighborhood and see all these Dumpsters, all these good building materials being thrown away,” said McCalmont. “We used three Dumpsters of trash. We were feeling bad about that, we thought it was a lot. But the deconstruction firm said that normally eleven Dumpsters are required” for a similar size project.

Many of the greenest strategies can’t be seen because they’re under the house or behind the walls. More than half of the existing house was retrofitted with a new foundation for earthquake safety, which involved shoring up the framing, pouring a new foundation, and setting the framing back down. Seismic retrofitting increases the likelihood that the building will remain usable for many generations.


	Click photos for larger view.

For the new framing, all the major timbers are engineered lumber, and most of the solid lumber and plywood is certified by the Forest Stewardship Council (FSC) to have been sustainably harvested. The builders reused many of the existing framing members. The old exterior redwood siding was sandblasted, clearcoated and reused in the home’s interior.

Walter points out that reusing materials requires more effort. “You have to clean the lumber up,” he said, “and some reused lumber can only be used for nonstructural purposes. Making sure it’s used appropriately requires education and due diligence by the supervisor.”

Lyon added, “It takes more time and costs more money, but there are environmental and psychological impacts that aren’t measurable. You’re saving the cost of transporting new material, you’re not putting it in the landfill, and you’re saving forests.”

Other green materials include cabinets made with FSC-certified plywood and FSC-certified wood veneers, and recycled glass countertops.

Water Conservation

The home’s new water distribution system uses small diameter, flexible cross-linked polyethylene (PEX) pipes that run directly to the fixtures from manifolds located near the water heaters. This alternative to typical branched piping decreases the volume of water in individual pipes and saves water and water heating energy. PEX piping is less expensive to install than copper, and is now allowed by code throughout California.

New high efficiency toilets were installed that use 1.28 gallons per flush (federal code requires no more than 1.6 gallons per flush). The low-flow showerheads and bathroom faucets also exceed federal code requirements for water conservation. Other water-saving features include a water-efficient clothes washer and an on-demand recirculation control pump that reduces the time it takes for hot water to reach the faucets.

Outside, the McCalmonts are planning new water-conserving landscaping. Instead of turf, the property will be planted with mostly California native and Mediterranean species that require little irrigation water.

A high efficiency irrigation system will be installed with a smart controller turns on the irrigation system only when soil and weather conditions warrant it. Topsoil will be amended with compost and planting beds dressed with mulch to conserve soil moisture and improve soil quality. The McCalmonts also plan to install a rainwater harvesting system.

Community & Living Green

The project received GreenPoint Rated points for being located in a built urban setting with utilities already in place. Accessibility features include a zero step entrance, interior doors and passageways on the main floor that have at least 32-inch clear passage space, and blocking for grab bars in main floor bathrooms.

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