The most recent blogs at Green Building Advisor

Court Blows Away Permits for Wind Turbine Eagle Kills

Posted on October 1, 2015 by Stuart Kaplow in Guest Blogs

On August 11, a federal court set aside the U.S. Fish and Wildlife Service (FWS) rule allowing 30-year permits to “take” bald and golden eagles. In an industry born from tax credits and government energy policies, an interruption of one of those key policies can bring wind turbine construction to a halt.

The Department of Energy Chooses a Definition for Net Zero

Posted on September 30, 2015 by Allison A. Bailes III, PhD, GBA Advisor in Building Science

A few weeks ago, I wrote about whether homes that produce as much energy as they use should be called net zero energy or zero net energy homes. Several readers offered up another choice: zero energy homes.

Managing Job-Site Mud

Posted on September 30, 2015 by Fernando Pages Ruiz in Green Building Blog

Drive past an average construction site (even a small residential addition) after a summer rain, and the street is usually coated with mud. Gooey, sticky, dirty stuff, the mud that runs off job sites and flows into storm sewers wreaks havoc on the quality of streams, rivers, and other waterways. But beyond the dire environmental consequences of job-site runoff, it’s also rude to mire your neighbors in mud. Plus, there’s the matter of steep fines.

Creating High-Performance Walls

Posted on September 29, 2015 by Zack Semke in Guest Blogs

Our Evolution of Enclosure exhibit at AIA Portland (which ran through September 10) examined the role that buildings — especially building enclosures — can play in helping to diffuse climate change. As examples, the exhibit drew on four projects built by Hammer & Hand: Karuna House designed by Holst Architecture; Pumpkin Ridge Passive HouseA residential building construction standard requiring very low levels of air leakage, very high levels of insulation, and windows with a very low U-factor. Developed in the early 1990s by Bo Adamson and Wolfgang Feist, the standard is now promoted by the Passivhaus Institut in Darmstadt, Germany. To meet the standard, a home must have an infiltration rate no greater than 0.60 AC/H @ 50 pascals, a maximum annual heating energy use of 15 kWh per square meter (4,755 Btu per square foot), a maximum annual cooling energy use of 15 kWh per square meter (1.39 kWh per square foot), and maximum source energy use for all purposes of 120 kWh per square meter (11.1 kWh per square foot). The standard recommends, but does not require, a maximum design heating load of 10 W per square meter and windows with a maximum U-factor of 0.14. The Passivhaus standard was developed for buildings in central and northern Europe; efforts are underway to clarify the best techniques to achieve the standard for buildings in hot climates. and Glasswood Commercial Retrofit, both designed by Scott | Edwards Architecture; and Madrona Passsive House, designed by SHED Architecture & Design.

Battling Condensation on Attic Ducts

Posted on September 28, 2015 by Scott Gibson in Q&A Spotlight

Jimmy Miller is trying to solve a condensation mystery in a Florida ranch-style home that is being renovated. Even though the air conditioning equipment appears to be operating normally, humidity inside the house is between 60% and 65%, and return ducts located in the attic show significant condensation.

Air Leakage Through Spray Polyurethane Foam

Posted on September 25, 2015 by Martin Holladay, GBA Advisor in Musings of an Energy Nerd

Many builders use spray polyurethane foam as an air barrierBuilding assembly components that work as a system to restrict air flow through the building envelope. Air barriers may or may not act as a vapor barrier. The air barrier can be on the exterior, the interior of the assembly, or both., raising the question: How thick does the spray foam layer have to be to stop air flow? There's a follow-up question, of course: Is the answer different for open-cell spray foam than for closed-cell spray foam?

As with most building science questions, there is a short answer and a long answer. The short answer is that closed-cell spray foam needs to be at least 1 or 1.5 inch thick to act as an air barrier, while open-cell spray foam needs to be between 3.0 and 5.5 inches thick to act as an air barrier.

In Clash of Greens, a Case for Large-Scale Solar

Posted on September 24, 2015 by Philip Warburg in Guest Blogs

If the United States and the world community hope to avoid the worst effects of climate change, solar power will have to play a pivotal role in electricity production. The technology is quickly maturing, and the price of solar panels has plummeted to the point where new utility-scale solar installations are a sound investment, cheaper than new coal plants and frequently competitive with natural gas.

How to Become a Building Enclosure Control Freak

Posted on September 23, 2015 by Allison A. Bailes III, PhD, GBA Advisor in Building Science

Frank Lloyd Wright was a control freak. This was a guy who not only designed houses but also all of the trim details and even the furniture.

Undamming Rivers Could Make Room for PV

Posted on September 22, 2015 by Karin Limburg and John Waldman in Guest Blogs

Hydroelectric power is often touted as clean energy, but this claim is true only in the narrow sense of not causing air pollution. In many places, such as the U.S. East Coast, hydroelectric dams have damaged the ecological integrity of nearly every major river and have decimated runs of migratory fish.

Solar Decathlon: The Search for the Best Carbon-Neutral House

Posted on September 21, 2015 by Crystal Gammon in Guest Blogs

What’s the latest in well-designed, energy-efficient solar homes? The U.S. Department of Energy (DOEUnited States Department of Energy.) has invited teams from colleges across the country to design and build solar-powered houses that are cost-effective, energy-efficient, and attractive.

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