Over at tech site tech hive, they are calling a house in Utah "America's most energy-efficient home." They are really excited about it (they have sent me six press releases), for good reason; it is an interesting house. The builder, Garbett Homes, teamed up with Vivint, a home automation company, to build what could pass as a typical suburban home.
“Utah is not a tree-hugger state,” said Garbett Homes marketing director Rene Oehlerking. “Everyone wants to go green, but no one wants to pay to go green. We’re a small builder, but we’re not a custom builder. Our business model is to build production homes.”
It's not crazy expensive either.
The Zero Home defies the home-of-the-future stereotype of being too impractical for large-scale implementation: “This home is designed to be replicated on a mass basis,” said Oehlerking. “It costs about $150 per square foot to build a home like this—the same amount it costs our competitors to build conventional homes.”
There is a lot to like about this house, designed by KTGY Architecture and planning. It includes advanced framing that reduces thermal bridging through the studs, lots of insulation, a big Venmar energy recovery ventilator with HEPA filters.
Up on the roof there are solar thermal collectors that preheat domestic water, as well as 10 Kilowatts of photovoltaic panels, which are owned by Vivint, which sells the power to the homeowner or to the local utility. This keeps the possible $ 40,000 cost of the installation out of the house price.
Looking at Green building page of Garbett's website, one gets the impression that they actually are building "Homes that are healthy, energy efficient and environmentally responsible." The Vivint smart home technology is indeed impressive.
The difference between Net Zero and Energy Efficiency"
The problems begin with the title of the post, calling it "America's most energy-efficient home." It's simply not. there is a fundamental difference between energy efficiency and net-zero energy; you can make a canvas tent net-zero if you connect it to enough solar panels. The term Net-zero is really problematic because it tells you absolutely nothing about the house itself.
Energy efficiency, on the other hand, tells you a lot about the house itself. The most energy efficient homes in America are probably built to Passivhaus standards like the Park Passive in Seattle, which has its roof and slab insulated to R-100 and its 15" thick walls to R-60, with triple-glazed windows. Really energy-efficient houses don't depend on massive banks of photovoltaics; they depend on body heat. The difference between the two concepts is considerable.
Embodied energy and Transportation Energy Intensity
There are also other kinds of energy to be considered, besides the operating energy. There is the embodied energy of building a 4300 square foot house with the four garages; it takes a lot of material to do it. That's why serious green builders today look to build smaller homes.
There is the Transportation energy that comes from living in a home with a walkscore of 9. At least there is a plug for an electric car in the garage. There is seriously nothing within walking distance, even the nearest bus stop is .81 miles away. That's the main reason this house is able to come onto the market at a price the builder considers "affordable"; it's in Sprawlville where the land is cheap.
It won't feel like net-zero to the owner, either; while the owners will be paying 20% below market for their electricity from the solar panels on the roof, they are going to need that power to run this house. They don't have much of a choice; Michael Brown at Tech-hive notices that there are a lot of windows in the house but that most don't open.
After hearing how airtight the home was, I asked how the homeowner would get fresh air into the house. Turns out I gave Oehlerking the perfect transition to explain the Zero Home’s heating and air-conditioning system…. The ERV combines a heat exchanger with a ventilation system that continuously replaces the air inside the house with air from outside the house, removing the need to open windows to let in fresh air.
This house depends on the mix of green gizmos of fans, solar panels, ERVs and smart thermostats to be livable.
The Zero Home is the first smart home design that is highly replicable, affordable, and scalable. Instead of costing over $1 million, these homes can now be purchased starting at just $350,000. Together, Vivint and Garbett are making smart, green living accessible to everyone.
I could spend the next week contradicting every adjective in the paragraph above. Or I could just say that it is a big deal when production builders start taking a serious look at green building. Just don't call it "America's most energy-efficient home." It's not even close.