The most recent blogs at Green Building Advisor

Can Open-Cell Foam Waste be Used as Attic Insulation?

Posted on January 17, 2011 by Scott Gibson in Q&A Spotlight

UPDATED 1/19/11 with comments from Peter Yost

Open-cell polyurethane foam expands dramatically as soon as it hits its target, rapidly filling wall cavities and typically mushrooming beyond the stud line. After it's firmed up, installers trim away the excess so drywall or other wall finishes can be put up.

Questions and Answers About Air Barriers

Posted on January 14, 2011 by Martin Holladay, GBA Advisor in Musings of an Energy Nerd

UPDATED on December 12, 2014

Builders of a certain age — say, those older than about 55 or 60 — started their careers at a time when no one talked about air leakage or air barriers. Back in the early 1970s, even engineers were ignorant about air leakage in buildings, because the basic research hadn’t been done yet.

Times have changed, and most residential building codes now require builders to include details designed to reduce air leakage. Today’s young carpenters are working on job sites where air barriers matter.

Energy Return on Investment

Posted on January 12, 2011 by Alex Wilson in Energy Solutions

For the past few weeks, I've been writing about petroleum: what it is, the history of petroleum use, and what's ahead for this ubiquitous energy source that, to a significant extent, defines our society.

Announcing the Green Home Advantage Program

Posted on January 12, 2011 by Amy Hook in Green Communities

In Atlanta, Enterprise and The Home Depot Foundation have joined forces to create the Green Home Advantage program. The program ensures that all properties acquired through the federal Neighborhood Stabilization Program (NSP) in Atlanta meet a set of baseline green requirements developed by Enterprise and the City of Atlanta.

The program also offers technical assistance, trainings, and the opportunity for green certification.

In Mali, Mud Hut Upgrades Are Nixed by World Heritage Label

Posted on January 12, 2011 by Carl Seville, GBA Advisor in Green Building Curmudgeon

I’ve never been there, but according to a recent article in the New York Times (sorry if I am relying on this paper too much for inspiration), the city of Djenne, Mali, is a veritable museum of historic mud brick buildings. Among them is the Grand Mosque, the largest mud brick, or adobe, building in the world, originally built in the 13th century and replaced with the current building in 1907.

Is Double-Stud Wall Construction the Path to Efficiency on a Budget?

Posted on January 10, 2011 by Scott Gibson in Q&A Spotlight

UPDATED with an expert opinion from Bruce King

Writing from Glacier, Washington, Karen Bean faces a home-building dilemma that confronts many thousands of people: what's the best way to insulate the walls of her new house on a modest budget?

She has $150,000 to spend on the two-bedroom, two-bathroom house, which she plans to build on a foundation originally intended for a traditional house. Although the concrete-block foundation is well made, it's not necessarily well matched to the double 2x4 walls she's hoping to use.

Net-Zero-Energy versus Passivhaus

Posted on January 7, 2011 by Martin Holladay, GBA Advisor in Musings of an Energy Nerd

In Europe, builders interested in energy efficiency are gravitating to the PassivhausA 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. standard. Meanwhile, American researchers — and a few American builders — have developed a fascination with the idea of the net-zero-energy house. The U.S. Department of Energy has established as a goal that new buildings in the U.S. will be built to a net-zero-energy standard by 2030.

Blog Review: Energy Vanguard Blog

Posted on January 7, 2011 by GBA Team in Green Building Blog

by Martin Holladay is launching a new feature: periodic reviews of interesting blogs. To get the ball rolling, I’m recommending the Energy Vanguard blog.

The author of the Energy Vanguard blog, Allison Bailes of Decatur, Georgia, is a RESNET-accredited energy consultant and trainer. He performs heat loss calculations, provides HERS rating services, and provides rater training and 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. training, among other services.

Is There a Downside to Lumpy Attic Insulation?

Posted on January 6, 2011 by Allison A. Bailes III, PhD, GBA Advisor in Building Science

If your attic is going to have 50 bags of insulation blown into it, does it make much of a difference if it goes in flat or lumpy?

One reason that I'm interested in the question is that my dissertation in grad school was called “Flat or Lumpy.” (Of course, it had the requisite incomprehensibility in the subtitle, with words like “heteroepitaxy.”) Those two words in the title, which cut to the heart of what my surface physics research was all about, also describe a property of insulation that's important in building science.

Thoughts on the Future of Petroleum

Posted on January 5, 2011 by Alex Wilson in Energy Solutions

It's fitting that this first blog of 2011 takes a look into the crystal ball — at the energy source that pretty-much defines our culture.

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