Green Building Blog

By Martin Holladay

Everybody has an opinion on windows, it seems. When specifying windows, builders usually look for good customer service. Most builders want a local rep who answers the phone, provides quick turnarounds on bids, delivers windows on time, and promptly shows up on site when something goes wrong.

Homeowners want windows that look good, operate smoothly, and don't fall apart.

Energy nerds want windows with excellent performance specifications.

On my thousand-mile quality assurance road trip last week, I visited a house that was designed to produce more energy than it uses, making it a net zeroProducing as much energy on an annual basis as one consumes on site, usually with renewable energy sources such as photovoltaics or small-scale wind turbines. Calculating net-zero energy can be difficult, particularly in grid-tied renewable energy systems, because of transmission losses in power lines and other considerations. energy home. You can take any house all the way to net zero just by giving it enough on-site power production (photovoltaics, wind, hydropower...), but that's not the most effective way to achieve the goal of net zero energy use. First, you want to make the house really efficient, and that's what these folks did.

Reprinted with permission from Construct Ireland magazine.

The building-science-and-beer group that meets every month in Portland, Maine, recently launched a discussion of suggested specifications for a “pretty good house” — a house that seeks to balance construction cost and energy performance without being constrained by the dictates of existing green building programs or rating systems. Michael Maines's blog on that topic has generated dozens of comments, and GBAGreenBuildingAdvisor.com has received several e-mails from readers with suggestions for regional variations on the “pretty good house” concept.

Last week we published this photo as part of our “What’s Wrong With This Picture?” series. The photo shows a substandard fiberglass insulation job that was representative of an entire residential subdivision that hoped to qualify for Energy StarLabeling system sponsored by the Environmental Protection Agency and the US Department of Energy for labeling the most energy-efficient products on the market; applies to a wide range of products, from computers and office equipment to refrigerators and air conditioners.. Examples like this show that quality control by HERSIndex or scoring system for energy efficiency established by the Residential Energy Services Network (RESNET) that compares a given home to a Home Energy Rating System (HERS) Reference Home based on the 2006 International Energy Conservation Code. A home matching the reference home has a HERS Index of 100. The lower a home’s HERS Index, the more energy efficient it is. A typical existing home has a HERS Index of 130; a net zero energy home has a HERS Index of 0. Older versions of the HERS index were based on a scale that was largely just the opposite in structure--a HERS rating of 100 represented a net zero energy home, while the reference home had a score of 80. There are issues that complicate converting old to new or new to old scores, but the basic formula is: New HERS index = (100 - Old HERS score) * 5. raters is a weak link in the Energy Star program.

In many areas of the country, homes are receiving Energy Star labels they don’t deserve. Major errors like the ones shown in this photo are supposed to be caught by the HERS rater who performs third-party verification services. This home slipped through the cracks.

The photo shows at least four errors serious enough to have prevented the home from receiving an Energy Star label. Can you spot them?

Next week, we will post the answers that a Building America team, BIRA, came up with.

Reprinted with permission from Construct Ireland magazine.

Last week, GBAGreenBuildingAdvisor.com published a photo of a crawl space in an old house under the headline, “What's Wrong With This Picture?”

The photo showed an unvented crawl space in a cold climate. The home was built in 1885. This crawl space is attached to an adjacent concrete-floored basement. The foundation walls are made of mortared limestone.

Scroll down this page to see a construction site video of the Karuna House in Yamhill County, Oregon, showing the installation of capillaryForces that lift water or pull it through porous materials, such as concrete. The tendency of a material to wick water due to the surface tension of the water molecules. break material on top of the footings to prevent moisture from wicking up the foundation walls.

The Karuna House was designed by Holst Architecture and is being built by Hammer & Hand of Portland, Oregon.

You might call Ty Newell the reluctant engineer. At the University of Michigan in the early 1970s, he would rather have studied natural resources or liberal arts, but those programs were full. So he went into engineering, figuring he’d switch to one of his first choices in a semester or so.

Except that it never happened. His grade point average wasn’t high enough to get him into natural resources, and the prospect of being drafted for duty in Vietnam kept him from dropping out of school. So engineering it was going to be.