9) The Bottle Wall + the Trombe Wall

Having grown up with a copy of the Whole Earth Catalog on my desk (circa 1970) I've always been intrigued by doing things basically and naturally. And I guess I should admit right now I'm no enviro-wacko. I'm green, just not government green. I think rather than using police force to cause environmental action, you should use appeals to what is right, and change people's minds. And if that doesn't work, use market forces. OK, I'll admit it, I'm a libertarian. You can call us conservative hippies. I like that description. But enough about politics...

Straight from the late '60's back-to-the-earth movement is the idea of the EarthShip. Off-the-grid homes that use natural and recycled building materials. As you will see through this journey, the SunCottage tries to follow the EarthShip precepts.

One idea, both beautiful and renewable, is the BottleWall. A concrete wall made of discarded bottles, that, yep, are free. What's interesting is that one of the main supporters of the concept was the owner of Heineken beer. After a trip to the Caribbean and seeing beaches littered with abandoned beer containers, combined with a lack of affordable building materials, he came up with the idea of the WoBo, or World Bottle, a 'brick that holds beer'. Solves two problems at once, you gotta love it! Unfortunately the company didn't back his initiative, something about cost or profit, and Heineken bottle returned to it's familiar unsustainable round shape. But bottlewalls have an even older history. In 1905 a man in Death Valley created a house made out of 51,000 beer bottles contributed by local saloons. Check it out at Rhyolite, Nevada.

And while walls made of bottles can work in well in dry, warm environments, like the American South West, they won't cut it in Northern New England. Not enough insulative value, you'd freeze to death.

So this is where another passive house concept comes in: the Trombe Wall. Basically a Trombe wall is a vertical thermal mass that the sun's energy warms during the day, acting as a solar battery. Air heated on the dark-colored wall rises to the ceiling and is vented into the house, cool air flows in at ground level to replace it. It's essentially a passive solar air heater. So what we want to do in the SunCottage is combine the two to create a Trombe bottle wall. An added benefit is with the sun shining through them, they're beautiful! Here are a few examples:

We decided to locate our bottle wall on the east side of the lower floor exercise room. Two feet from a large bank of windows to maximize the incident morning light. We envision the design as a landscape, the same landscape you'd see out the window: a lake, mountains, trees, fields, sky and clouds. Here's a rough, half-completed sketch:

The next step is collecting bottles, we used our own, those from local bars, and from dumps and recycle centers where most of them live. Our 7' x 9' foot wall will require more than a thousand bottles. Green-colored bottles which represented leafy trees were easy, think Heineken or Pellegrino. Brown not so hard, Budweiser, most often. Clear, for the clouds, are mostly iced tea containers. The blues were tough, we started drinking a lot of Saratoga water. But by far the most sought after and hardest to find were small and large Bombay gin bottles, dazzling light blue for the undersides of the clouds. The sun was the hardest to figure out... there are no yellow bottles! So what we did was to glue yellow stained glass fragments inside clear bottles. The wall itself is traditionally made by laying mortar in, plopping in the bottles, and laying in another layer of mortar and bottles. We came up with a different strategy. Rather than building the wall one bottle at a time, in place, what we came up with was to pre-build the wall in our main house basement. Modular like... Using 3 x 5 sheets of bathroom rockwall with holes drilled through to set the bottles. We used 2 inch Styrofoam insulation to hold the bottles and make the walls safe to transport over to the SunCottage. These walls will be set in place and mortar added around them from the bottom up.

Construction of the modules started in November, it was completed three months later, here's some pics of the process:

Laying out the bottles:

Cutting the bottles: A masonry blade saws a bottle in half cleanly.

Two halves taped together:

Collected blues:

Our plan is to set the bottle wall 20 inches from the window bank to allow for access and cleaning. The 'sun' side will be painted black for maximum solar energy absorption. The 'room' side will be white or perhaps painted as a mural. We're looking forward to see how it works out.