The most recent blogs at Green Building Advisor

Flatrock Passive: A Final Design and Energy Modeling

Posted on July 4, 2017 by David Goodyear in Guest Blogs

Editor's Note: This is the second installment in a series of blogs by David Goodyear describing the construction of his new home in Flatrock, Newfoundland. The home will be the first in the province to be built to the 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. standard. The first installment of the GBAGreenBuildingAdvisor.com blog series was titled An Introduction to the Flatrock Passive House. You can find Goodyear's complete blog here.

Solar Thermal is NOT Dead

Posted on July 3, 2017 by ROBERT STARR in Guest Blogs

An article written by Martin Holladay, “Solar Thermal is Dead,” was published by GBAGreenBuildingAdvisor.com on March 23, 2012, and another article titled “Solar Thermal is Really, Really Dead” followed it on December 26, 2014. The premise of these articles is that solar thermal is dead because “It’s now cheaper to use a photovoltaic(PV) Generation of electricity directly from sunlight. A photovoltaic cell has no moving parts; electrons are energized by sunlight and result in current flow. system to heat domestic hot water.” These two articles have been very widely circulated and remain very much with us today. As one example, I recently Googled “solar domestic water heater” and these articles came up #2.

R-Value Advice from Building Science Corporation

Posted on June 30, 2017 by Martin Holladay in Musings of an Energy Nerd

To reduce energy use, green builders often install above-code levels of insulation. Thick insulation is expensive, however, so it’s sometimes hard to know how much insulation is optimal.

To help guide builders wrestling with R-valueMeasure of resistance to heat flow; the higher the R-value, the lower the heat loss. The inverse of U-factor. questions, I wrote an article in May 2016 (“How Much Insulation Is Too Much?”) reporting on R-value recommendations from three energy experts: David White, Marc Rosenbaum, and Rachel Wagner.

Unlocking the High Value of Clean Energy in Low-Income Communities

Posted on June 29, 2017 by David Labrador in Guest Blogs

Many of the 135 stakeholders of RMI’s Electricity Innovation Lab (e–Lab) who gathered for the first e–Lab Summit at the end of 2016 are involved with Leap, an ongoing RMI initiative dedicated to empowering and improving the lives of low-income communities and households in a clean energy future.

Air Sealing the Ceiling Joists in an Attached Garage

Posted on June 28, 2017 by Allison A. Bailes III, PhD in Building Science

The I-joists in the lead photo here run across the top of the wall between the dining room and the attached garage in this home under construction in the Atlanta area. In the old days, before anyone worried about air moving through those joist cavities, the builder didn’t bother to do anything beyond securing the joists.

You can see here, though, that the builder of this home knows a thing or two about air sealing because they've put blocking between the joists. But what do they do next?

Urban Rustic: Details for an Insulated Foundation

Posted on June 27, 2017 by Eric Whetzel in Guest Blogs

Editor's note: This post is one of a series by Eric Whetzel about the design and construction of his house in Palatine, Illinois, a suburb of Chicago. The first blog in his series was called An Introduction to a New Passive House Project. For more details, see Eric's blog, Kimchi & Kraut.

Keeping Cool in Detroit

Posted on June 26, 2017 by Scott Gibson in Q&A Spotlight

Like many houses built in the 1960s, Nathan Efrusy's 2,000-square-foot colonial in Detroit has baseboard heat but no central air. A single wall-mounted air conditioner keeps the first floor of the house comfortable, but Efrusy would like to extend AC to the second floor — the question is now to do that effectively.

In a Q&A post, Efrusy says he's been given several options for cooling on the second floor, but he's leaning towards a ductless minisplit.

In Praise of Scientists and Scholars

Posted on June 23, 2017 by Martin Holladay in Musings of an Energy Nerd

Most educated Americans still listen to scientists and believe in established methods of scholarly inquiry. That said, a strange side effect of our country’s recent slide into extreme political polarization has been an increase in the number of Americans who reject the conclusions of scientists and scholars.

Combining Sheathing With a WRB and Air Barrier

Posted on June 22, 2017 by Peter Yost in Building Science

Full Disclosure: First, there are a lot of different ways to get continuous air and water control layers on the exterior of a building enclosure. You can use housewrap, taped-and-sealed rigid foam insulation, liquid-applied membrane, or either the Huber Zip or Georgia-Pacific ForceField system. Each approach has strengths and weaknesses.

Companies Should Take Charge of the Potential Toxins in Common Products

Posted on June 21, 2017 by Anonymous in Guest Blogs

By DANA CORDELL, DENA FAM, and NICK FLORIN

Editor's note: The authors are Australian.

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