I’ve been looking for a house recently, and learning all kinds of new things in the process. Lately, I’ve been learning about the home inspection process, and discovering that beyond the basic local requirements, there are some optional tests you can do, including testing for radon. The more I learn, the more I think that testing your home for radon is a good idea for just about everyone.

Radon is a colorless, odorless radioactive gas. It’s found in low levels in many homes, but some homes have higher concentrations, which are linked to an increased risk of lung cancer. You can test for radon with a DIY kit, or have your home professionally tested.

If your home does have elevated levels of radon, it’s relatively easy to find and fix the problem. And since that’s the case, why not go ahead and find out if your home has high radon levels? For anyone trying to create a greener, healthier home, improving your indoor air quality is a great place to start, and testing for radon is a simple step toward that goal.

For more information, check out the EPA’s very helpful website on indoor air quality, which includes a Citizen’s Guide to Radon. The EPA also had a video contest last year to educate people about radon testing. Here’s the full list of radon video entries. (See below for my personal favorite. These are dogs with a message.)

Earlier this month I visited Greensburg, Kan., and toured a few of its many green buildings. It was a great trip, and you can see more photos from my visit in this Greensburg photo gallery.

Background. Greensburg is the rural Midwestern town that was struck by an EF5 tornado on May 4, 2007. The storm was 1.7 miles wide — it killed 11 people and destroyed most of the town.

After the storm, the people of Greensburg made a commitment to rebuilding the town as a model green community. That effort is already well underway, and you can even watch its progress on TV. A Greensburg TV series on the Planet Green network is following the progress of rebuilding. The third season begins filming soon.

My visit.  Mother Earth News is based in Topeka, Kan., so Greensburg is relatively close to where we’re located — about a 4 hour drive — but this was my first visit to the town. I took a walking tour guided by volunteers from Greensburg Greentown, a community-based nonprofit devoted to helping Greensburg build green.

So what does Greensburg look like these days? Well, there’s still a lot of evidence of the storm, even more than two years out. As our tour guides explained, Greensburg used to be locally known for its trees, but now most of the trees are gone. You can see from one end of town to the other — the view is wide open. Most of the storm debris is gone, too, but there are still remnants of many buildings — a wall here, some steps there. But already many homes and buildings have been rebuilt, and many more are under construction.

There are nine different buildings on the walking tour of Greensburg (some you can go into, and others are just visible from the street). While there are many green features to see, I was struck by one recurring theme: concrete. Many of the buildings are being built with insulated concrete form walls (ICFs). In fact, ICF construction makes a lot of sense for Greensburg. Not only does it provide excellent insulation, the buildings are also structurally strong, and therefore very resistant to storm damage. From a green standpoint, one of the disadvantages of concrete is that it takes a lot of energy to produce. But in Greensburg, there are always more opportunities to go green — in this case by recycling concrete debris from the storm. The Silo Eco-Home in Greensburg is made of precast concrete, and 35 percent of that concrete is recycled from local storm debris.

Another noticeable fact about Greensburg: There are renewable energy systems everywhere, especially on the new city buildings. The arts center has wind turbines, city hall has building-integrated solar panels, and many buildings have renewable energy systems that are not readily visible from the street, including rooftop solar panels and underground geothermal heating and cooling systems.

If you want to visit.  For anyone who’s interested in renewable energy or green building, Greensburg is a great place to visit. You can simply walk up and down Main Street and see numerous examples of eco-friendly building in action, and even more green buildings are planned for the future. One exciting project is the Chain of EcoHomes being planned by Greensburg Greentown. This project is designed to help visitors understand the green options available to homeowners.

If you’re in the area, don’t miss the chance to stop by and check out what’s happening, and be sure to check in with Greensburg Greentown for more information about tours. You can also download their self-guided tour booklet for much more information about the green features of individual buildings.

Cheerful, albeit exhausted solar decathletes are headed home this week after 21 days of excitement on the National Mall.

For the second decathlon in a row, Team Germany took first place, impressing judges and peers with their SurPLUShome, which used the maximum building dimensions acceptable by competition standards. In addition to first place overall, Team Germany was  recognized for excellence in the Architecture, Lighting Design, Comfort Zone, and Hot Water contests.

University of Illinois at Urbana-Champaign took second place with Gable Home, a small home intended to pay tribute to its cultural roots while integrating advanced solar technology.

Team California’s Refract House took third with its innovative design and excellence in Architecture, Communications, Engineering and Market Viability contests.

Check out the video below to see Team Germany’s reaction when the Solar Decathlon 2009 winners are announced.

To get the whole story on this year's Solar Decathlon, take a look at these previous updates.

It's Almost Time for the 2009 Solar Decathlon
The Houses Leave Home
The Little House from a Big Town

I just ran across this interesting video about straw bale building posted over on Lloyd Kahn’s blog. It’s about the Builders without Borders Straw Bale Eco-house, which was constructed and exhibited in Washington, D.C., during the summer of 2008.

The video shows many of the steps involved in the construction of this load-bearing straw bale house, including how they deal with the problem of too much moisture in the straw. Straw bale building enthusiasts and regular Mother Earth News readers may see a few familiar names, too. The members of the building team include Catherine Wanek and Bill and Athena Steen. Take a look!

A few years ago, we had a “most beautiful chicken coop” contest. The winner? A cordwood chicken coop.

Cordwood construction is sometimes also called “stackwood construction.” A cordwood building consists of short, round pieces of wood (think firewood) held together with mortar.

While the look of cordwood construction can take some getting used to, personally, I find it very appealing. These buildings are especially attractive when multicolored glass is incorporated into the structure by placing glass bottles in the walls.

But there are plenty of other reasons to consider cordwood for all types of building projects, large and small. The method of construction is reasonably simple, and the materials are readily available — two good reasons cordwood has been popular with DIY builders for many years. And there are ecological reasons to consider cordwood construction, too. You can probably get the wood locally, so it doesn’t need to be shipped long distances, and the thick wooden walls of a cordwood building provide great insulation.

Here’s a fun video tour of a cordwood cabin. Take a look, and also check out the additional resources below.

Cordwood Articles from the Mother Earth News Archive:

• The Charm of Cordwood Construction

• The Return of the Cordwood House

• A Century (or More) of Stackwood Homes

• The Cordwood Sauna

• A Child-built Cordwood Clubhouse

Other Cordwood Resources:

• Cordwoodmasonry.com is the online home of Rob and Jaki Roy and the Earthwood Building School.

• There’s a whole cordwood chapter from the digital book Building Green on the Nauhaus Idea Repository.

• Greenhomebuilding.com has a nice cordwood page.

• The All Things Cordwood section at Daycreek.com, includes a great photo album.

White roofs, aka cool roofs, have caught attention lately as an offbeat but relatively simple and effective strategy for reducing air conditioning costs and greenhouse gas emissions.

The idea is simple: white reflects heat instead of absorbing it. It's also a favorite idea of Energy Secretary Steven Chu, who said "when you're thinking of putting on a new roof, make it white" in his appearance last month on The Daily Show with Jon Stewart (you can watch the video below).  Chu added that white roofs costs about the same as traditional black roofs and for those in a warm climate, a white roof can reduce air conditioning costs up to about 20 percent.

When Chu talks white roofs, he cites research from Art Rosenfeld, the commissioner of the California Energy Commission. Rosenfeld calculated that pervasive white roofs and white streets throughout the United States would create a significant reduction in carbon dioxide emissions — the equivalent to getting rid of all cars for 11 years. You can learn more about Rosenfeld and his passion for energy efficiency by watching the second video below.

The New York Times also covered cool roofs in White Roofs Catch On as Energy Cost Cutters.

"We come home on days when it’s over 100 degrees outside, and the house is at 80 degrees,” white roof owner Jon Waldrep of Sacremento, Calif., told The New York Times.  

According to research by the Lawrence Berkeley National Laboratory, nearly every state could see significant reductions in carbon dioxide emissions if 80 percent of commerical buildings were converted to have white roofs, even if white roofs meant increased heating demands in winter. You can see how much each state would save in Imagining a Cool-Roof Nation.

So what do you think? Should commercial buildings switch to white roofs? What about for your home? If it meant significant savings in your air conditioning bills, would you choose a white (or lightly colored) roof the next time you need new shingles? Or would that be too much of a color clash? Share your thoughts by posting a comment below.

Say you had $1,000 to invest in green home improvement — how would you spend it? 

Don't worry about where the money came from — if you must, say you earned it, or it came from the green home improvement leprechaun.

Would you buy new, energy-efficient windows? Or bamboo flooring for the living room? What about more insulation for the attic to help lower your heating and cooling bills? What about an on-demand water heater? Or perhaps an upgrade for the exterior of your house, such as a new paint job or fiber-cement siding? Speaking of paint, would you add new color to rooms with low- or no-VOC paint? Would you want new, energy-efficient appliances, such as a new refrigerator? In general, would you want to focus on energy-efficiency improvements to help you save money over time? Or aesthetic improvements you can feel good about?

Obviously $1,000 may not cover all expenses for some of these projects, especially at a large scale. But take a second to daydream: If you were handed a grand of green to make your home more green, what would you most want to do? Share your daydreams by posting a comment below.