The most recent blogs at Green Building Advisor

R-Value Scammers Sued By the FTC

Posted on December 30, 2016 by Martin Holladay in Musings of an Energy Nerd

Here at, we received our first inquiry concerning Insultex housewrap on July 31, 2015, when Marcus Sheffer questioned the validity of Insultex’s R-valueMeasure of resistance to heat flow; the higher the R-value, the lower the heat loss. The inverse of U-factor. claims.

Insultex is a plastic housewrap distributed by Innovative Designs of Pittsburgh, Pennsylvania. The company offers two versions of its housewrap, at a price that is from two to nine times higher than the price of ordinary housewrap. One version is 1 mm (0.0384 inch) thick; according to Innovative Designs, this product has an R-rating of R-3. That’s R-78 per inch.

Wolfe Island Passive: Adding the Insulation

Posted on December 29, 2016 by David Murakami Wood in Guest Blogs

Editor's note: David and Kayo Murakami Wood are building what they hope will be Ontario's first certified 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. on Wolfe Island, the largest of the Thousand Islands on the St. Lawrence River. They are documenting their work at their blog, Wolfe Island Passive House. For a list of earlier posts in this series, see the sidebar below.

On-Site Storage Is the Great Equalizer

Posted on December 28, 2016 by Bruce Sullivan in Guest Blogs

We are now in a world where decentralized electricity production, such as rooftop solar, is more viable than ever for the public and more threatening than ever to utilities. The public is more willing to adopt in-home renewables thanks to reliable technology, solid performance, declining costs, and the growing availability of loans.

Passive House in China, Part 2

Posted on December 27, 2016 by Katrin Klingenberg in Guest Blogs

Editor's note: This is the second installment of a two-part blog series. The first installment was Passive House in China, Part 1.

The 3rd China Passive Building Summit in Shanghai was followed up by a one-day expert meeting and workshop. The workshop participants rode out together to the Old Town of Shanghai, a nice area of the city consisting of mostly low-rise buildings. The fall weather had finally turned a little nippy and drizzlier than the days before, and I was happy to have worn my jacket that day.

Nearing the Home Stretch

Posted on December 26, 2016 by Carl Seville in Green Building Curmudgeon

Carl Seville and his wife are building themselves a new home in Decatur, Georgia. The first blog in this series was titled The Third Time’s the Charm. Links to all of the blogs in this series can be found in the “Related Articles” sidebar below.

Songs for Christmas 2016

Posted on December 23, 2016 by Martin Holladay in Musings of an Energy Nerd

Donald Trump’s Song

Oh, the weather outside is frightful,
But the new AC is delightful,
I’ll tell you what I’ve always felt:
Let it melt! Let it melt! Let it melt!

Polar bears these days are thinking
That the ice cap seems to be shrinking,
I’ll tell you what I’ve always felt:
Let it melt! Let it melt! Let it melt!

The heat shows no signs of stopping,
And the corn in the fields is popping,
I’ll tell you what I’ve always felt:
Let it melt! Let it melt! Let it melt!

We expect a most wild ride,
Because it’s so hot outside,

Pete’s Puzzle: Mold in Certain Closets

Posted on December 22, 2016 by Peter Yost in Building Science

Author’s Note: I am setting up a series of building investigations that I have done over the years as puzzles, presenting successive pieces as an interesting way to tell the story. As with any story, you can read the end first if you want, but that approach cuts down on the drama (admittedly not a bad thing for some folks…)

The Uniform Mechanical Code Looks to Limit Flex Duct

Posted on December 21, 2016 by Allison A. Bailes III, PhD in Building Science

Some people love flex duct. Some people hate it. Some of us are OK with it if it's done right.

As I've documented here numerous times, many flex duct installations leave a lot to be desired. They sag. They're kinked. They're twisted around pipes.

If there's something bad that can be done with flex duct, someone has done it. And the result of all those mangled flex duct installs is poor air flow, which creates comfort problems, uses more energy, and is one reason systems get oversized.

From Theory to Reality: Building a Net-Zero Home

Posted on December 20, 2016 by Thomas Lambert in Guest Blogs

Can you really build a net-zero-energy house based on information learned from an online course? The short answer is yes, and we have CreekSide 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. to prove it.

My wife and I are often asked two questions: Why did we build a net zero energy house? How did we know how to build it?

The "why" is really an evolution of our values — of “walking the talk.” We have always been eco-minded and dreamed of doing something with alternative energy to reduce our carbon footprintAmount of carbon dioxide and other greenhouse gases that a person, community, industry, or other entity contributes to the atmosphere through energy use, transportation, and other means. .

Upgrading a Crawl Space

Posted on December 19, 2016 by Scott Gibson in Q&A Spotlight

David Meyer's Seattle-area home is built over a crawl space, and after stripping out the old insulation and vapor barrier he is ready to re-insulate and seal the area. After looking into his options, Meyer is leaning toward "encapsulation," meaning the crawl space would be sealed (unvented), with the insulation on the walls, not between the floor joists.

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