Passive House Goes High Tech

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The Happy Meadows Courtyard House in Chapel Hill, NC, features passive building science and technology to produce enough energy to power the house and more.

Chapel Hill, North Carolina, is an interesting place for homebuilders. In a 25-mile radius are some amazing green homes. The Home Builders Association of Durham-Orange-Chatham Counties even put together a program called Green Homes of the Triangle, which drew attention to green homes and green building techniques at a home tour in May.  

“It’s a small but very fertile niche in Chapel Hill, a small bubble. If you went 20 or 30 miles in any direction people would be less interested in spending more to save more, but in Chapel Hill and the county around us, people understand the investment, and the return on it,” homebuilder Kevin Murphy says.

Murphy is the owner of Newphire Building Corp., a small custom homebuilder in Chapel Hill that focuses on using green building techniques that save his clients thousands of dollars in energy and water bills each year. His latest home features geothermal with a ground source heat pump, a hybrid hot water heater, conditioning energy recovery ventilator (CERV), CertainTeed drywall, solar photovoltaics on the roof and a D’mand water recirculator.

The latest Newphire home is so uber-efficient and environmentally friendly that when it is completed, it is projected to earn the National Association of Homebuilders Green Builders’ Standard Emerald certification, the standard’s highest rating. So far it’s met or exceeded the top sustainable third party verifications including a HERS rating of -1, PHIUS Plus from the Passive House Institute of the U.S., and DOE Challenge House (Dept. of Energy). The house is expected to be LEED Platinum.

Newphire Home unfinished exterior

It’s even got a name, the Happy Meadows Courtyard House.

“This is one of the most uber-green houses I’ve ever seen,” says the project’s architect Arielle Schechter. “We can owe that to the client because he kept pushing us for ever-greener materials. He did his research and an educated client is valuable in this field.  He really was a great inspiration [and] I appreciate his involvement.” 

 

Taking Green to the Next Level

Murphy, a former member of the Peace Corps who has a bachelor’s in geography, a master’s in education, and is a certified Passive House Builder, says his experiences in Paraguay, where he and his wife lived in a 10-by-12-foot house with no electricity or running water, helped them realize that living efficiently was something the people of Paraguay did very well. He also realized his dream was to build environmentally friendly homes. 

The one-story single family house is 2,567 heated square feet, with three bedrooms plus an exercise room that could function as a fourth bedroom.  The home features an understated entry from the north side, opening to large windows that allow in light and a view from the south. The master bedroom is a spacious room right off the courtyard and connected to a comfortable master bath that includes a zero threshold shower for aging in place. The guest room is designed to function as a caregiver’s suite in the future if needed.  This room has a small coffee bar area that can convert to a kitchenette and has a bathroom, of course.  


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The owner, who is 81 years old, is still a practicing therapist and his office is fully functional with file storage, a custom desk made of reclaimed red gum wood, and tons of bookcases.

The house packs a ton of storage discreetly so that everything fits. Schechter claims she is a storage fanatic.

One of the most important rooms to the clients is the “mega mudroom” which has multiple functions.  It is the everyday entry from the garage, with a long bench and shoe storage, coat closet, vacuum storage, mail sorting area, charging station, laundry area and a microscopy station with space for a microscope and slides for the owner’s hobby.

The kitchen is made from all plywood with no added formaldehyde.  No VOC (volatile organic compound) products were used inside.  The entire house has Energy Star appliances and fixtures.

 

Passive construction with green technology

The home includes many passive construction features that make the technologies used worthwhile.

“None of the technologies are worth it if you don’t do the passive building,” Schechter says. “These are things that we have done for thousands of years that fell out of favor.”

Newphire home with elevations surrounding the exteriorPassive features such as deep overhangs that block the sun at its highest and hottest, triple-pane windows facing the south side, and aiming the home toward the prevailing winds in order to cool it easily while using less energy. The home also has a super-insulating building envelope, to maintain the temperature just where the homeowner wants it without using a lot of energy to keep it there. These building techniques were once standard but had fallen out of use over the past century, however with energy efficiency becoming a necessity in new homes, the time-tested building techniques are coming back into vogue and augmented with modern advances in green building materials.

The walls are prefab insulated concrete panels, built offsite in two days and assembled on site in another two days with the help of a crane. The drywall is AirRenew Essential by CertainTeed and uses cutting edge “VOC scavenging” technology: the sheetrock absorbs any VOCs that might be in the air, rendering them inert and storing them inside the product indefinitely.

The home also has a white EPDM (ethylene propylene diene terpolymer) cool roof. The white membrane roof uses titanium dioxide to reflect UV rays and prevent it from attacking the polymer. In warm climates, white EPDM can reduce air-conditioning costs without sacrificing durability of the roofing system and because of its reflectivity, white EPDM is installed using mechanically attached or fully adhered systems

Technology takes over where passive energy savings end, resulting in a home that is not only net-zero for energy use, but may end up being net-positive, as in the home produces more energy than it actually needs.

The home has a 5.4-kilowatt solar array on the roof, which provides all the energy the home needs and more. That’s all the electricity Happy Meadows needs to make it a NetZero/Net Plus home, Schechter says.

Murphy says the client wanted enough electricity to power an electric vehicle, but he talked him out of it because the client doesn’t own one yet. “Monetarily speaking it does not benefit the owners. … Utilities are required by law to purchase renewable back but they buy it at an unfavorable rate from the homeowner and any surplus they knock off the rate. It’s not ideal,” Murphy said, before adding. “How cool would that be if more of our cars and houses produced all the energy we needed? We’re not burning coal or diesel or gas.”

ClimateMaster ground source heat pump

Happy Meadows is heated and cooled by a ClimateMaster ground source heat pump with a Nest thermostat, which leans the homeowners’ tendencies and adjusts the heating and cooling to fit their rhythms and save energy. A GE GeoSpring hybrid water heater with heat pump technology provides the home with hot water and saves up to $635 a year in the average household. The hybrid water heater uses 1,830 kWh per year and provides the same amount of hot water as a traditional 50-gallon standard electric water heater.

When the water in the pipes cools, the D’mand hot water recirculator by Kontrols Systems sends the slug of cool water in the plumbing system back into the water heater. Once the unit senses that the water has reached the target temperature for hot water, the pump shuts off.  When you get in the shower, or go to use hot water for another purpose, the water is hot instantly. 

 


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Since this house is built tight, it needs extra ventilation in order to maintain good air quality. A motorized damper for the dryer and range hood has a sensor that activates when the dryer or range hood are in use and opens a damper. The opening allows outside air to enter the house so the house does not become depressurized.

CERV by Build Equinox

Standard ventilation is done by a CERV by Build Equinox. The system includes the “CERVICE” option that provides the homeowner with real time diagnostics from anywhere with Internet access, it also allows the homeowner to set levels of humidity, carbon dioxide, and VOCs. The CERV brings in fresh air as needed according to the settings. “The manufacturer, Ben Newell, suggests that if you have someone pet-sitting while you are on vacation, you will be able to see when they arrive and leave based on the spike in CO2 while they are there!  Pretty cool,” Murphy said.

 

Newphire home with solar powered pump for pool and water garden

Other energy features include a solar powered water pump for the water feature in the Happy Meadow’s yard. The pump, designed by Southern Energy Management is a portable system with a single PV panel, battery and a pump. It will power the waterfall.

The homeowners also want a keyless entry system and are debating using a biometric fingerprint-reading lock with Wi-Fi capabilities. To protect their green home, they have also installed an alarm system with a video feature to see who is at the front door before opening it.

 

Style with substance

Newphire Home exterior 1200 gallon underground cistern

Just because the home is energy efficient doesn’t mean the architect forgot about style.

Two old growth cypress logs that sunk hundreds of years ago into the Catawba River, which makes up the border between North and South Carolina, were hauled up from the river bottom and milled into planks used for wall paneling and cabinetry in the master bedroom. Scrap blocks of rare granite that had been sitting in a quarry were milled and installed as countertops.

The floors are cork in the kitchen and gym and concrete throughout the rest of the home.

Finally, a 1,200-gallon underground cistern will collect almost 100 percent of the rainwater from the home’s roof.  The home also includes a wildlife habitat and frog pond. “So far it is a huge success and has become a great wildlife viewing place as well, as many different species come to drink from the frog pond,” Schechter says.

The final cost of the home hasn’t been calculated yet, since construction isn’t complete, but that should be done by the end of September.

About The Author

Casey Meserve is a TecHome Builder Staff Writer, creating investigative and timely articles for its eMagazine and Special Reports. She graduated from Bridgewater State University with a master’s degree in English in 2011. She began her writing career in 2005 as a reporter for Community Newspaper Company and later GateHouse Media. From 2010 to 2013, she worked as an editor at AOL Patch.

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