The most recent blogs at Green Building Advisor

The majority of our electricity in the United States is generated by using a heat source to boil water and produce high-pressure steam, which then spins a steam turbine hooked up to a generator. To generate this steam, our utility companies burn fossil fuels like coal and natural gas, or—as with Vermont Yankee—they rely on the heat of nuclear fission. (Only hydropower, wind, and solar electricity generation do not rely on a heat source and production of steam.)

While energy prices have dropped from their record highs a few months ago, many area residents are still wondering how they’ll pay for heat this winter. The most common fuel in northern New England, heating oil, is still priced at over $4.00 per gallon.

But how does the price of oil compare with the price of other fuels and electricity? That sounds like a simple enough question, but it’s actually fairly complicated.

In this final installment about insulation we’ll take a look at the family of rigid boardstock materials. Unlike fiberous or spray-foam insulation that is installed in wall or ceiling cavities between the studs, rafters, or joists, boardstock insulation is applied either on the interior or exterior surface, spanning across the framing.

Bottles are greener than cans, but is beer the greenest choice?

In a quest to discover the most environmentally benign beverage for backyard barbecues, one builder sifted through the options to help us drink greener.

I have nothing against water: I make coffee with it, paddle a canoe in it, and I even drink it every day. But it's not always what my empty hand is looking for when I settle down in the backyard and fire up the Weber.

Air sealing and insulating are a great first step, but switching fuels is a lot quicker and easier. I'll do the insulating after I get a bonus check!

I was standing in the cold on a dark December night, pouring diesel fuel from a five-gallon jug into the side of my house, when it really clicked: Houses consume a huge amount of oil. I had always gotten uptight about gas mileage in my cars and trucks (I had a full-size Ford pickup at the time) but, until that cold night, how much our houses gobble up had never really hit home.

[This blog has been edited to correct some information on Tripolymer Foam. I continue to wish for greater transparency in the manufacturing industry. -Alex Wilson]

In recent columns, we’ve looked at cellulose insulationThermal insulation made from recycled newspaper or other wastepaper; often treated with borates for fire and insect protection. as well as fiberglass and other batt insulationInsulation, usually of fiberglass or mineral wool and often faced with paper, typically installed between studs in walls and between joists in ceiling cavities. Correct installation is crucial to performance. materials. The other option for filling wall and ceiling cavities is foam insulation that is sprayed into the cavity. There are several such materials that are used for this application, all installed by professional insulation contractors.

Last week’s column addressed cellulose insulationThermal insulation made from recycled newspaper or other wastepaper; often treated with borates for fire and insect protection., which is the greenest and one of the most effective insulation materials available. But it isn’t always practical or affordable to install cellulose. To insulate walls with cellulose, it’s usually necessary to hire an insulation contractor, and if the job is very small—bumping out and reinsulating one wall of your home, for example—the cost may be prohibitive for that small improvement. This is where batt insulationInsulation, usually of fiberglass or mineral wool and often faced with paper, typically installed between studs in walls and between joists in ceiling cavities. Correct installation is crucial to performance. makes sense.

Insulation is our number-one line of defense against high heating costs, and my favorite type of insulation is cellulose. Along with its effectiveness at slowing heat flow, cellulose insulationThermal insulation made from recycled newspaper or other wastepaper; often treated with borates for fire and insect protection. is a green product — made mostly out of an abundant waste product: old newspaper.

There is no component of a home more important in minimizing energy costs than insulation. Insulation is the material used in walls, ceilings, roofs, and foundations that slows the flow of heat.

Like a lot of people, I‘m often running late. One of our two cars—a five-year-old Honda Civic Hybrid—has a digital readout showing fuel economy. Because I travel so much (ironically hopping on a plane or driving hours to lecture about energy savings or green building), I get lots of opportunity to track my mileage. When I’m running late and have to speed down to the airport—sometimes pushing my luck at 70-75 miles per hour—I find my mileage running about 40-42 mpg. On a more relaxed return drive at 60 or even 55 mph, my fuel economy jumps by 20% or more—to over 50 mpg.