The most recent blogs at Green Building Advisor

Does a Crawl Space Make Sense?

Posted on November 24, 2014 by Scott Gibson in Q&A Spotlight

Michael Geoghegan is designing a house for a mixed, humid climate and he plans on using an insulated crawl space.

Heat Transfer When Roasting a Turkey

Posted on November 21, 2014 by Martin Holladay, GBA Advisor in Musings of an Energy Nerd

Recently I decided to research heat transfer during turkey roasting. It turns out that this issue has been extensively studied by physicists and engineers.

As with houses, there are two basic camps: those who use computer modeling and those who make measurements. Some researchers feel more comfortable at a desk with a laptop; others feel more comfortable in a kitchen with a thermometer.

In Maine, A Passivhaus School Takes Shape

Posted on November 20, 2014 by Scott Gibson in Green Building Blog

For now, you'll have to use your imagination to envision a new school on the wooded site a few miles north of Portland, Maine. There are only concrete stem walls outlining the shape of the building, and earth-moving equipment up in back shaping what will eventually become recreation fields.

But by next June, visitors should be able to see the new Friends School of Portland. The 15,000-square-foot building will be one of only a few 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. school buildings in the country, and the largest Passivhaus structure in Maine. Architects also plan on making it a net-zero energyProducing 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. building.

How NOT to Install Windows in a New Home

Posted on November 19, 2014 by Allison A. Bailes III, PhD, GBA Advisor in Building Science

I see a lot of interesting stuff at construction sites and in people's homes. I also see stuff I never got to see because people send me photos. I like photos! Remember that
ice chest someone had incorporated into a duct system? That was sent to me. So are the first two photos in this article.

Connecting to the Grid Can Be Expensive

Posted on November 18, 2014 by Alexi Arango in Guest Blogs

As they set out to build a single-family 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. on Potwine Lane in Amherst, Massachusetts, Alexi Arango and LeeAnn Kim asked themselves, “Is it possible to live without burning fossil fuels?” One measure of success would be meeting their goal of net-zero energyProducing 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. performance. This is the eighth blog in a series.

Straw-Bale Walls for Northern Climates

Posted on November 17, 2014 by ben graham in Guest Blogs

The mechanical baler was invented in the 1850s (Reynolds, History of Hay Balers), and it's been a while now since those folks in the Midwest put up a couple of bale houses. You would think that by now we would have very refined construction techniques for straw-bale construction, given that some of those original buildings are still standing. Well, we are getting there.

All About Basements

Posted on November 14, 2014 by Martin Holladay, GBA Advisor in Musings of an Energy Nerd

Foundation discussions can get heated. For some reason, builders often dig in their heels when the topic of slabs versus crawl spaces versus basements comes up. It’s time to declare a truce.

It’s perfectly possible to build a great house on any one of these three foundation types, as long as everything is properly detailed. Each type of foundation has advantages as well as disadvantages. If you have a foundation type that you prefer, that’s great. I’m not going to try to change your mind.

The Largest Passivhaus Building in the U.S.

Posted on November 13, 2014 by Mike Steffen in Guest Blogs

In Portland’s western suburbs, a structure is on the rise that could change the face of affordable housing in America. Situated adjacent to the Orenco Station light rail transit stop in Hillsboro, Oregon, the Orchards at Orenco will provide 57 units of housing. The project sponsor, REACH Community Development, is aiming to achieve 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. certification. When complete in the spring of 2015, Orchards at Orenco is slated to be the largest Passivhaus-certified building in North America.

Calculating Heating Degree Days

Posted on November 12, 2014 by Allison A. Bailes III, PhD, GBA Advisor in Building Science

Let's say you did some work on your home to make it more energy-efficient: air sealing, more attic insulation, and a duct system retrofit. You've got your energy bills for 12 months before and 12 months after you did the work, and now you want to see how much energy you saved. So you sit down with all 24 months worth of utility bills, convert everything to a common unit if you use more than one type of fuel, and take a look at the numbers.

A First Look at the Official WELL Building Standard

Posted on November 11, 2014 by Carl Seville, GBA Advisor in Green Building Curmudgeon

When I first heard about the WELL building standard, in a New York Times article, I was both amused and offended, and trashed it appropriately in a blog.

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