Green Home Building and Sustainable Architecture

Sustainable architecture is an exciting and important field, with many people reviving traditional methods of building and others creating innovations to established practices. Kelly Hart, webmaster of the popular website, posts text and photos featuring what he discovers from around the world.

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Location: Crestone, Colorado, United States

Kelly Hart has been involved with green building concepts for much of his life. He has also worked in various fields of communication media, including still photography, cinematography, animation, video production and now website development. Kelly has lived in an earthbag/papercrete home that he built and consults about sustainable building design.

May 18, 2006

Avoiding Gridlock in your Home

The typical gridlock image is of being stuck in your automobile in a traffic system that has bogged down because it cannot handle the volume of traffic. You feel helpless because you have to use the car, but it's not getting you where you want to go. You are locked into a dysfunctional system.

I use the term “gridlock” in your home to refer to a similar situation: you are locked into using the electrical power grid because it seems you have no choice, and if you look at the big picture, the system is dysfunctional. Electricity provided by the grid, at least here in the southwest, comes primarily from coal. Burning our finite supplies of fossil fuel to produce energy, with the byproduct of considerable pollution--especially the carbon dioxide that is increasingly blamed for global warming--would have to be considered dysfunctional.

According to our local electric company, the use of electricity has been escalating, even though they frequently advocate conservation. So what can we do? Conservation is certainly part of the answer, and later in this article I will make some suggestions about this. Going to an alternative, renewable and clean energy source is another possibility, but not without its costs.

In our home, we have chosen to go with a hybrid system for our electricity. We are connected to the grid and some of the circuits are fed by that, but we also have a small solar electric system that feeds the rest of the house. We have eight 75 Watt panels that are fixed on the roof. They send 12 volt DC power to a dozen golf cart batteries in a vented compartment under some stairs. This stored power is then turned into regular household 110 volt AC power by an inverter that feeds the electricity through the breaker panel to certain circuits. Solar power basically runs our refrigerator/freezer, our clothes washing machine, most of the lights in the house, and miscellaneous small appliances (like the fax machine and photocopier). The kitchen circuits, the computers, and the video and television equipment are all served by the grid. If there isn't enough sunlight to keep the batteries charged sufficiently, the inverter will automatically recharge the batteries from the grid power. This system cost us approximately $8,000, with me doing the installation. It may never pay back its cost in actual dollars, but the real payback is in knowing that we are doing what we can to avoid GRIDLOCK.

If you choose to use alternative energy for your electricity, photovoltaic (solar), is probably the best choice for many areas that get plenty of sun. Hydroelectric can work if you happen to have a stream running through your property. Wind power usually requires rather consistent wind to be worth installing. Solar electric systems are fairly complex, and require some knowledge and expertise to install. You might want the advice or help from someone with experience.

Whether you use alternative energy or not, conservation should be the name of the game. (With stand-alone alternative systems, you are forced to conserve, or there won't be enough juice to run the show.) Some big consumers to avoid are everything that heats with electricity, like space heaters, electric stoves, water heaters, and clothes dryers. Air conditioners also use a lot of electricity; evaporative coolers are much more efficient, especially in arid localities. Compact fluorescent lights use about a third the energy of regular incandescent bulbs, and they last much longer. So even though they cost more initially, it pays in the end.

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May 13, 2006

Digging In for Comfort

Think of all the animals who dig into the ground to find refuge, comfort, security. Their ancestors discovered millennia ago that the earth could provide all of that, free for the digging. We humans have done this too, at times, but we tend to forget the benefits, preferring to follow the trend of building on the surface.

What the animals know is that the earth can shelter them from the extremes of temperature, from the wind and sun and snow. If you dig several feet into the ground, you will discover that the temperature does not vary much there, year round. Water pipes are usually buried because they won't freeze when below frost level. In fact, the temperature five feet under the ground stays about the same year round. I'm sure you have experienced the delicious coolness of a basement room on a scorching summer day. Perhaps you've gone into that same basement in mid-winter and been surprised how warm it felt. This is the moderating effect of the earth at work.

Of course, most of us would not be comfortable in a house kept at 50 degrees, so we would need to bring the temperature up maybe 20 degrees to relax at home. Compare that 20 degree increase with say the 70 degree increase necessary to be comfortable in a conventional home when it's zero outside. It would take over three times as much energy to stay warm if you have not taken advantage of the earth for shelter. And on a hot day it works in the other direction, requiring tremendous air conditioning energy to stay cool enough, if you have not dug into the earth.

Many people think that an earth-sheltered house must be dark, dank, dirty and doubtful as a pleasant abode. They are wrong. There are many ways to introduce light, views, and an airy feeling into a bermed house. I'm not suggesting that we live in a hole in the ground, although even that can be pleasant if the hole is big enough to provide an atrium/central courtyard. More commonly, an earth-sheltered house is dug into a hillside, especially if that hillside faces more or less south. Then the windows for solar heating are naturally at ground level, and much of the rest of the house can be surrounded with earth. Of course, even on flat land, soil can be pushed up around the sides of the house to provide the berm.

In building an earth-sheltered house, it is important to pay attention to certain details. As with the rest of the house, the walls that are in contact with the earth need to be well insulated, or else the soil would continually suck the warmth out of the house. Also, these walls need to be strong enough to withstand the pressure of that earth and waterproof to keep out the moisture. Traditionally, reinforced concrete has been used to build subsurface walls, and this works well, but it is not the most environmentally friendly way to do it.

Mike Oeler, in his books on building underground, suggests using heavy timbers to frame the structure, with boards to form the walls, and then using plastic sheeting to waterproof it. He has lived in such a structure in Idaho for quite a few years and is still happily advocating this approach.

I have been experimenting with earthbag construction, much of which is underground. The polypropylene bags were filled with either sand or volcanic scoria. The lower bags that are filled with sand are insulated from the outside with scoria. I covered all of this with a double layer of 6 mil polyethylene before backfilling. Between each course of bags are two strands of four-point barbed wire. The wall itself has a convex curve set against the earth to withstand the pressure of the soil. The beauty of this is in the simplicity of construction and the fact that it uses very little industrial material.

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