Sunday, April 25, 2010

Starting the envelope

The foundation walls are up and the workers are laying the 2" Dow Styrofoam Scoreboard insulation against the walls. This forms the continuous insulation (R-10) and moisture barrier along the masonry wall that is vital to our conditioned crawl space. It takes the place of any insulation that would normally be against the floor. The joints between pieces are sealed with expanding spray foam sealant, creating the continuous barrier. There will be a vinyl strip below the installed insulation that we will seal the floor vapor barrier to, once the house is dried in. It is already clear in watching the workers, that while thoughtful design and product choice are important in reaching the desired energy goals, correct application and attention to detail is equally important. It is noted that Dow STYROFOAM products are CFC Free, they do not contain fully halogenated chlorofluorocarbons (CFCs) regulated by the United Nations Environment Program (UNEP) in the Montreal Protocol.

Saturday, April 17, 2010

An enlightening experience...

In striving for an zero energy home, once your heating and cooling load has been reduced through a tight, well insulated house envelope and geothermal heating/cooling system, your appliances and lighting become a proportionally more significant issue. In looking to reduce lighting energy demands, the use of more energy efficient, long lasting CFLs and LEDs becomes paramount. In recently searching for lighting fixtures designed specifically for these types of bulbs, we found the local "pickings" to be sparse and expensive. Searching online was somewhat more successful, with sites like, and offering more choice of fixtures, and,,,, and offering access to quality bulbs at reasonable prices. We have decided to primarily go with CFLs in conventional CFL-compatible (read: hides the bulb) fixtures, while using longer lasting but more expensive LEDs in key recessed lighting and undercabinet locations. We plan to use cooler color bulbs (5000K)in closets and dressing areas, where their greater accuracy is useful. In the remaining areas, we will be using warmer bulbs (2700K) bulbs for their flattering glow. Part of being a successful "early adopter" is having a high frustration tolerance and a healthy dose of initiative, imagination and stubbornness. It is sometimes tempting to simply yield to the easy, available and less immediately expensive answer, but that will rarely get you to your goal. Plus we plan to enjoy the projected 34 years of use of those little LEDs.

Wednesday, April 7, 2010

A Greener Foundation

When we visited the build site this week, we saw cement trucks and a tall pumper (the tall River City boom in the picture) busy pouring our foundation. In talking with our EarthCraft builder, we learned that he is using fly ash concrete, a form of concrete which replaces some of the cement in the mixture with fly ash, the fine powdery residue from coal combustion. This produces a concrete that is stronger, more durable and easier to work with and diverts that fly ash generated by our coal-fired power plants from ending up in our landfills. Fly ash containing concrete mixes can receive LEED credit under the guidelines established by US Green Building Council. In the vein of there being nothing new under the sun, a form of volcanic fly ash concrete was used by the Romans in building the Coliseum and the first domestic use of fly ash concrete was in 1929 in the construction of the Hoover Dam.