When Paul Holland and Linda Yates set out to build a the “greenest home in America” on the Portola Valley, Calif. hillside where Linda grew up, they envisioned something that would debunk the myths that green building was ugly, too expensive and alters your lifestyle. It would also adhere to four principals of sustainable and “regenerative” building: energy, materials, water and habitat.
There would be renewable energies, reclaimed building materials, graywater and blackwater recycling, solar technologies and lots of insulation.
Along the way. the self-styled eco-geeks learned a valuable lesson. After a comprehensive audit of how they would use their home, design consultants advised eliminating an entire basement space because of the energy it would consume.
Homeowner Linda Yates calls it her “Aha” moment. “In the end, energy trumps everything,” she says.
The design change helped frame the couple’s thinking in making this the greenest house in America—or at least one of the greenest. Much of this super-green home revolves around energy conservation, from the passive solar siting of the home to the water conservation systems and to energy-saving electronics like super-efficient Xicato LED lighting, occupancy sensors, motorized window treatments and a home control system that’s operated almost exclusively from the owners’ iPads.
Powerhouse of Efficiency
Tah.Mah.Lah, as the house is called, is named for the Native American Ohlone word for puma or mountain lion, and sits in the hills above Silicon Valley tech havens Palo Alto and Menlo Park, where Paul Holland works for venture capital firm Foundation Capital, a company that invests a portion of its funds in green and clean tech ventures.
No one knows for certain whether Holland and Yates’ home is actually the greenest home in America, but it’s certainly in the running. The house accumulated a LEED Platinum score of 122.5 and could have achieved 153 points if LEED overseer USGBC awarded more points to technology and innovation. Yates is driven to get the USGBC to recognize more LEED points for innovation and technology. The house also earned Energy Star, Indoor AirPlus and California’s Build It Green designations.
This is a 5,600-square-foot powerhouse of green and green technology, from the 27-kw, 120-panel solar array sized to power the house and five electric vehicle chargers to the geothermal system for heating and cooling to the FSC-certified wood, native stone, blown-in R-42 Johns Mansville ceiling insulation, triple-glazed SeriousWindows and Tigo solar panel boosters. You name it here, and it’s green.
For it all, energy efficiency and conservation was a key driver.
Designing for Efficiency
In building a house like this, it’s important to design to reduce your energy needs first, then look to offset the rest through alternative energies like solar. “Designing [and siting the house] for big windows and lots of light allows both solar gain and the ability to never turn lights on until it is dark. The passive solar gain we get is extraordinary, meaning we need almost no heat in the winter,” Yates explains.
Integrating building science for optimal airflow and efficiency is also very important. The siting of the home helped the water conservation systems as well. “Putting the house where it is means we get the benefit of gravity for the flows of the black and graywater into the filtering system for subsurface irrigation and rainwater into the cistern,” Yates says.
Water Conservation = Energy Savings
Conserving water and repurposing water is huge, especially in dry areas like California. That’s a no-brainer, but saving water also saves energy, and not just in a home’s pumps and heating. “One of the things we learned is that the biggest contributor of electricity in any municipality is the distribution and cleaning of water,” Yates says.
Holland and Yates’ home only uses city water for taps. The graywater from showers and blackwater from toilets goes through the septic system then through subsurface irrigation to water the yard’s meadow of native grasses that use 80 percent to 88 percent less water, Yates says.
Rainwater is collected in a 50,000-gallon cistern for re-use as well. Inside, hot water is produced by heat pumps tied to the underground geothermal heating system, which in turn uses pumps powered by the solar array.
Even the distribution of the hot water is efficient. Four D’Mand hot water recirculators deliver warm water to sinks without wasting cool water, which is voided back into the water tank for reheating.
A High-tech Efficiency Boost
To monitor conservation with the water systems, Holland and Yates can peek in on cistern levels via a web portal on their iPads. There are also apps for the in-floor heating, a weather station, the irrigation system, pool filtering and more.
Most of the home’s everyday functions can be controlled via their iPads and iPhones, or from keypads used in place of typical lighting switches in each area. Lights can be dimmed, scenes can be set, security can be armed, ventilation adjusted and audio and video controlled all from Holland and Yates’ mobile devices or those innocuous keypads.
A Control4 home control system ties most of these systems together, and is the finishing, all-encompassing touch in this sustainable home.
Remember those four sustainable and regenerative principals of energy, materials, water and habitat? They can all affect one another. For example, the type of roofing material and insulation affects energy use. “We wanted to go through each of those things and maximize efficiency,” Yates says. “Then leverage technology to either boost efficiency or manage the efficiency.”
That’s where the Control4 system and electronics installation company cyberManor of Los Gatos, Calif., came in. “It’s almost back to the future – going back to a simpler way that people lived through the centuries, but using technology to get back to that,” Yates says.
There’s no mad scientist, Michael J. Fox and DeLorean supercar here; what Yates means is achieving the energy usage of a simpler time, by using the technology available today.
The Control4 system can dim the LED lights, set scenes in which only the lights and music needed in one area come on, and turn off lights and devices when the security system is armed. The control system also automates the heat recovery ventilators (HRVs) that bring fresh air into the home, turning them on at different times, depending on the time of year and how much ventilation may be needed.
In addition, occupancy sensors throughout the home turn lights off after 10 minutes of room vacancy. And the Control4 system operates motorized MechoShades in the master suite, girls’ room and guest house, allowing sun in to warm the spaces.
Virtually all that is visible are the six-button keypads, each mounted on a cedar plank. Thermostats are located in a closet, with just small temperature sensors in spaces, further eliminating wall-clutter. The keypads are used mostly for enabling the preprogrammed lighting scenes, calling up music and recirculating the hot water where needed. The buttons are engraved for easy use.
“The system is so intuitive that our young children and guests can pick up an iPad and use all the features of the system without a list of lengthy instructions or training,” says Yates.
“One of the coolest parts is we made it all nearly invisible,” says cyberManor founder Gordon van Zuiden. There’s no technology cluttering the clean, open spaces—and much of the energy efficiency of this house in automated.
Entertainment isn’t left out, either. The Control4 system pumps Pandora Internet radio and other audio through the home’s built-in speakers and distributed video to LED TVs. There’s a nice 5,1-channel surround sound system in the library, and in bedrooms the TVs rise out of the floor on motorized lifts.
Automation Enhances Efficiency
Integrating various home systems on a common control platform eliminates the need for other devices and control screens. It also allows them to interact with each other more seamlessly.
“We have a button that allows us to turn off the whole front of the house as people are moving to the back to get ready for bed. It seems like a small thing, but it means we actually turn lights off more than we might if we had to go around to each room,” says Yates.
Many people, even in the green business, may not think an extensive electronics system can be efficient, but there are efficiencies atop efficiencies here. The LED-backlit TVs use less electricity than other TVs, and a Digital Logger device shuts down multiroom amplifiers during the day when no one is home. A BlueBolt power conditioner from Panamax can remotely reboot rack components as needed.
Energy monitoring is also planned. When planning their home, Holland and Yates had a plug load study conducted to reduce the power used by electronics systems as much as possible. Several monitoring systems have been looked at, and the owners and cyberManor hope to soon install one, likely enabling circuit-level monitoring. “We are all still waiting for the ultimate dashboard,” says Yates.
The Power (Savings) of Automation
So have automated electronics systems in this very green home helped it achieve other efficiencies?
Absolutely, says Yates. “Making it easy and automatic for people to be energy-efficient is key. With the control system, you can do more than just turn [devices] on and off. You can dim, you can manage plugs, you can manage multiple rooms at the same time, you can manage not just the house but the landscape from anywhere.
“But a control system alone does not make a house greener, she adds. “It is the icing on the cake. If the cake isn’t well designed and thoughtfully built right with the right intent in the first place, all the control systems in the world won’t make it greener.”
A Living Learning Center
To learn more about Tah.Mah.Lah, check out the home’s web site, which was created to help educate people in building and living more sustainably.
“One house cannot make a difference, but it can hopefully be the pebble in the pond that inspires someone else to go do the same. And it is in collective sustainable action that we can steward the earth,” Yates says.
Systems Design & Installation: cyberManor
Builder: MGM Construction
Architect: HKS Hill Glazier Studio
Energy Consultant: Integral Group
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