This House Consumes Less Net Energy Than Your Little Urban Studio
Three mornings a week, Bill Healy or Hunter Fanney lead tours for their government colleagues of the newest and most curious project on the campus of the National Institute of Standards and Technology in Gaithersburg, Maryland, a place where federal researchers tinker with wild ideas like refrigerants that could combat global warming and sensors that could measure human brain activity. This latest $2.5 million experiment went up slowly over the course of 18 months on a grassy lawn just inside the campus’ main entrance and across the street from its childcare center. So lots of people have been waiting to get a peek inside.
Set anywhere else – in fact, even just outside of NIST’s security gates in suburban Washington, D.C. – this laboratory would look entirely unremarkable. It is, by all appearances, a typical suburban American home. It has three upstairs bedrooms, 2,700 square feet of living space, another 1,500 square feet of unfinished basement, a detached two-car garage and the kind of yawning driveway you could spend an entire weekend shoveling in wintertime.
"Now," says Healy, starting a tour this week inside the two-car garage for a dozen curious colleagues, "this isn’t a small home."
Of course, he’s stating the obvious. But the size of this house is one of the most novel things about it. NIST believes that this home – with 10 kilowatts of photovoltaic panels on the roof, and another four solar thermal panels over the front porch – will generate as much energy as a four-person family can consume in a year. This is, in other words, a “net-zero” house. But most attempts at building such places have taken the form of futuristic or minimalist creations, of tiny pod homes or avant-garde construction.
"We wanted to show that it could be done in a normal house," says Healy, a group leader in NIST’s Energy and Environment Division. "We could have done small little pods, but we didn’t think that would really have the impact of showing what could be done in a real, American house."
This is, in fact, pretty close to the types of houses builders have been constructing for the last decade (not counting the recession). The average new home in America peaked in size at about 2,500 square feet in 2007. The inside of the NIST home, designed to be LEED Platinum by the firm Building Science Corporation, feels spacious but not quite excessive for a family of four. You could probably yell from one corner of the kitchen to a family member in the master bedroom.
This is the kind of home – already complete with wall sconces, built-in cabinets and warm paint tones – where a sizable share of Americans live (or, at least, aspire to). In the quest to combat climate change and reduce our energy consumption, it’s easy to sidestep this reality. Cities are inherently more energy efficient than the suburbs, just as apartment buildings and town homes do a better job of insulating and sharing energy than detached single-family houses do. We could put a pretty significant dent in America’s carbon footprint if everyone would just move from suburban houses that look like this one into urban, transit-oriented developments. But this is, of course, unrealistic.
If, on the other hand, American tastes for the 2,700 square-foot, two-car garage homestead don't change, we could at least change these homes themselves. Give them solar panels, double- and triple-paned windows, hyper-insulated walls that are twice as thick as typically built and the most energy efficient spaces on the market. Every advance in NIST’s net-zero home is currently available commercially, if not at Home Depot (it’s also possible to buy almost all of these things in America). This is the other piece of what this experiment is trying to prove: The typical suburban home can go net-zero, too – and right now, not 10 years down the road.
The project underscores that we probably need to invest in both of these futures: one where more people have the opportunity to move into dense and car-free urban neighborhoods, and the other where we recreate the alternative for people who don’t want to do that.
Building Science Corporation
The endeavor, funded by the American Recovery and Reinvestment Act, cost $2.5 million. But the actual cost of constructing a home like this is probably closer to $600,000 to $800,000 (not counting the value of the land below it). As part of its future research, NIST plans to study just what such a home might run you if it were located not on a government campus, but in a real Maryland subdivision.
At some point later this year, when all of the instrumentation is ready, the Energy and Environment Division will stop giving tours. At that point, the home will be sealed off for a year as researchers study it in living action. There will be no furniture in the house, and no real people, either. Instead, life with a typical family of four – including a 14 and 8-year-old – will be minutely simulated based on national data, with sensors turning on and off and consuming energy to the rhythms of a family’s morning coffee pot, evening TV time and nighttime showers. Any appliance found in more than 50 percent of American homes – hair driers, toasters, clocks – will be simulated. The people will be, too. When you breathe, after all, you produce humidity.
“People matter significantly in residential [buildings],” Healy says. The energy consumption in a large office building is effected more by equipment and large systems than individual people. But your home is different. How you use your home – how long you shower, how often you wash your clothes, where you set the thermostat – goes a long way toward determining how much energy your home uses.
Courtesy of NIST
If you were to press your face to a first-floor window of the NIST house later this year, you might see a faucet briefly running as if someone were washing dishes at the kitchen sink, or the lights dim as the invisible occupants retreat upstairs for bed. It sounds almost as if simulating this family will be a greater technical challenge than building the house was (when you put a hot casserole into a cold fridge, even that impacts energy use – and NIST has taken this into account, too).
But a virtual family, rather than a real one, will allow the researchers to more accurately test all of the building’s features and systems as they interact with each other. Product manufacturers, Healy says, are already lined up to work with NIST on the findings. NIST falls under the federal Department of Commerce, which means that a large part of its mission lies in pursuing research that could help American industries (and inform standards such as building code). In this case, it’s also pursuing research that most home builders, or air conditioning companies, would be unable or unlikely to do on their own.
"We certainly don’t want to publish data that says, ‘this looks great,’" Healy says, referring to a particular refrigerator or insulation brand. "We’re not Consumer Reports. We have to be careful of that. But we want to help industry evaluate how different technologies would work in a home."
Depending on where this house may be built in the real world, its location (and associated transportation) could offset some of its energy efficiency. But a subdivision of net-zero homes would still be a vast improvement on the status quo. And in some ways, these houses are also better prepared to take advantage of solar energy than an urban home beneath a dense tree canopy. A lot of the other technologies inside the NIST house are meant to work just as well for a detached home on five acres as for five smaller town homes on half of one. But the real innovation here is that you may have the option of choosing between either model in the very near future.