Touring the ultimate 'green' house

At 8,000 feet, near Aspen, Colo., a nonprofit called the Rocky Mountain Institute is demonstrating just how efficient residential living can be.

Daniel Terdiman Former Senior Writer / News
Daniel Terdiman is a senior writer at CNET News covering Twitter, Net culture, and everything in between.
Daniel Terdiman
7 min read

This is the front of the greenhouse at the home of Rocky Mountain Institute founder Amory Lovins. Daniel Terdiman/CNET

SNOWMASS, Colo.--Residential living doesn't get much more efficient than this.

Here, out in the country not far from the ritz and glamour of Aspen, you're more likely to find ranchers and wide-open farmland than movie stars. But what you will find, at the original headquarters of the Rocky Mountain Institute, a nonprofit sustainability think tank, is a house that could teach us all a few lessons in energy efficiency and comfort.

It is the home of RMI founder Amory Lovins and also serves as office space--though RMI's official headquarters is now nearby in Snowmass on a ranch property formerly owned by the late John Denver. The house has a series of systems built into it that are designed to provide all the power it needs, maintain a steady, comfortable temperature, keep it well lit, and even grow bananas at 8,000 feet.

As part of Road Trip 2009, my trek through the Rocky Mountain and Great Plains regions in search of the most interesting destinations, I got a tour of the facility Monday from RMI public relations manager Cory Lowe (see video below, which may require high volume). Lowe explained that the house is a manifestation of one of the nonprofit's three main focus areas. RMI consults worldwide on energy, transportation, and building issues. The house serves as a kind of physical portfolio piece for the latter.

Indeed, it is a prime example of one of RMI's chief directives: efficiency first, and then renewables. In other words, do everything you can to cut power usage and then supply what's still needed with renewable energy sources.

Among RMI's other projects are a $500 million retrofit and efficiency upgrade for New York City's Empire State Building and a long-term plan to help cities prepare for what many expect to be a future filled with electric cars.

But here in the wide-open spaces of Snowmass, the focus is on sustainable living. And from the moment you walk onto the property, you get a sense of what RMI is all about.

On the roof, which was built in 1982 but recently went through a significant renovation, is a "hodge-podge" of photo-voltaic panels. In the past, they provided a great deal of the building's electric power. But since the renovation and the addition of a new, large-scale set of solar panels, the house is now thought to be capable of producing 9.8 kilowatt hours, which is more power than it uses.

Part of that is due to two smaller solar panels that are installed on the far left side of the building's roof and which are designed to track the sun throughout the day. Most solar panels are south-facing and stationary, but thanks to a small tracking antenna mounted on their top-right corners, these two panels are able to stay in sync with the sun all day, meaning they provide 40 percent more power than traditional panels, Lowe said. They are also able to point to the brightest spot in the sky on cloudy days, meaning that even when it's overcast, they can still maximize their power production.

Photos: Modeling the uberefficient house

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Of course, energy efficiency doesn't come just from generating electricity. It also comes from the reduction in the use of energy. As a result, the house was designed so that it has no furnace and no traditional heating systems.

I said that the house reminded me of Earthships, a style of off-the-grid sustainable housing that are popular in places like New Mexico and that I wrote about during Road Trip 2007.

Lowe explained that, in fact, many of the design elements of the RMI house were "stolen" from Earthships. But after walking through the Snowmass house, I think that it's clear RMI took the concepts much further.

Both, however, are based on the idea of thermal mass, or the collection of heat in things like dirt, clay, concrete, water and plants. That's why both Earthships and the RMI house have large greenhouses as central features. But where the Earthships I visited near Taos, N.M., tended to have a very narrow greenhouse in front of south-facing windows, the RMI house had a very large, deep greenhouse that, in fact, is the building's central space.

An Earthship, as seen near Taos, N.M., is an off-the-grid type of housing that relies, like the RMI house, on thermal mass for heating. Daniel Terdiman/CNET

In addition, the greenhouse here is filled with gorgeous landscaping that includes a brook, a tiny pond filled with fish, a lot of cement in the floor and walkways, a fair amount of dirt and several banana trees.

The idea, explained Lowe, is that all these elements together form the thermal mass, which is designed to absorb heat for about six warm months, and then slowly release it during the colder months. This means that when the temperatures outside begin to drop--or get downright frosty in the high Rockies winter--the house stays comfortable without a furnace.

That, of course, is very similar to an Earthship. But Earthships require two main elements that the RMI house doesn't have and doesn't need: a back wall made mainly out of tires packed tight with dirt, and a hillside on the north side of the building that the house is built up against. By contrast, the RMI house was built out in the open.

The RMI house also requires no traditional water heater. Instead, it has a large, south-facing panel on the roof that is lined with pipes filled with an anti-freeze. As the sun warms the pipes, they warm the building's water supply through a heat exchange process. Like everything else here, this means that hot water is on demand at any time without the use of any externally provided power. If the water temperature isn't high enough, it can be boosted with a small, supplemental, solar-powered heater.

Another component of the house's use of efficient systems is a pair of what are known as Solatubes. On the roof, the house has mounted what look like very small chimneys, but which are actually a form of skylight. Underneath, two large, well-insulated tubes snake down inside the building, inside of which are a series of reflective mirrors. Finally, the tubes open up into the house's main hallway, providing a bath of sunlight that is filtered with a long screen. The upshot is that sunlight is directed into what would otherwise be a dark section of the house, without the need for a huge skylight.

Solatubes are not innovations unique to RMI, of course. Rather, they are popular all around the world. But they are yet another example of something that can be added to the average house to improve conditions without requiring additional power.

The light here is provided by two Solatubes mounted on the roof of the house. Daniel Terdiman/CNET

All told, RMI's house is designed to keep energy use low, provide what power it does need--and hopefully, feed some back to the grid. Lovins also directed that the house be outfitted with technology to help analyze every bit of power usage so that the RMI folks there can see, at any time, how it's performing. Part of that, Lowe explained, had to do with a desire to be as transparent as possible. He didn't say so explicitly, but my sense was that because the house is a showpiece for RMI's work, Lovins wanted to be able to show the world how the systems are performing.

And all around the house, the systems are on display. In the bathroom, there is a low-flow toilet, and a high-efficiency hand dryer. In the kitchen, the refrigerator and freezer have thick doors and walls for better insulation. And while the house used to use natural gas, allowing for a gas stove, it now features an electric stove.

There's also several rooms with rounded walls, which, Lowe said, are stronger than straight walls, and which help with sound aesthetics.

Ultimately, the idea is both for RMI's team to live and work in one of the most efficient and comfortable houses in the world, and for the think tank to be able to show to potential clients what is possible.

But it's not just about making the world better, Lowe explained. For RMI to convince its corporate clients to get on board, the firm has to make the case that the kinds of innovations featured in the house are also economically viable--that efficiency and sustainability can offer significant cost savings over legacy systems.

Still, when you're the one living, or working, in such a building, you want to know that your investment is worth the trouble.

"In order to live efficiently, you don't have to suffer," Lowe said. "Amory's old saying is, 'Hot showers and cold beer. You don't want to give them up just to live more efficiently.'"

For the next several weeks, Geek Gestalt will be on Road Trip 2009. After driving more than 12,000 miles in the Pacific Northwest, the Southwest, and the Southeast over the last three years, I'll be writing about and photographing the best in technology, science, military, nature, aviation, and more in Colorado, Utah, Idaho, Wyoming, Montana, and South Dakota. If you have a suggestion for someplace to visit, drop me a line. And in the meantime, join the Road Trip 2009 Facebook page and follow my Twitter feed.