The most recent blogs at Green Building Advisor

Twenty Below and Off the Grid

Posted on January 10, 2014 by Martin Holladay, GBA Advisor in Musings of an Energy Nerd

In a recent blog, Allison Bailes did a great job defining heat and explaining heat flow. It’s important to remember, though, that Allison Bailes lives in Atlanta. When the temperature drops to 6°F in Atlanta, the story makes national news. But when the temperature hits -20°F in Vermont, we just tell our kids to remember to wear a hat when they walk to school.

Minisplit Heat Pumps and Zero-Net-Energy Homes

Posted on January 9, 2014 by Marc Rosenbaum in Guest Blogs

For the last several years, just about every project I’ve worked on other than large university buildings has used minisplit heat pumps for heating and cooling. Why?

1 – There is no combustion and no need for a chimney or vent.

2 – In space conditioning applications, heat pumps can provide heating and cooling.

3 – The equipment installation costs and the operating costs compare favorably with other options.

4 – Heat pumps are a natural partner to solar electric systems to achieve zero-net-energy buildings.

Heating System Safety In Cold Weather

Posted on January 9, 2014 by Alex Wilson in Energy Solutions

The morning paper had yet another story about a destructive house fire — fortunately no fatalities (this time*), but the total loss of another home and another family’s belongings. And like many others, the culprit appears to have been the wood stove.

So many of the home fires we experience in Vermont result from trying to keep warm. Some have to do with faulty installation of wood heating equipment; many others result from improper operation of that equipment or management of the ash.

153 Green Building Acronyms and Initials

Posted on January 8, 2014 by Allison A. Bailes III, PhD, GBA Advisor in Building Science

Acronyms and initials (let's call that AI, for short, not to be confused with the other AI, which stands for artificial intelligence, or AIA, which stands for American Institute of Architects) are part of the jargon of every field. Our field, whether you call it building science, green building, home performance, or something else, is no exception.

A German Deep-Energy Retrofit

Posted on January 7, 2014 by Andrew Dey in Guest Blogs

I recently visited a job site on the outskirts of Berlin that had previously caught my eye. Although the buildings were shrouded in the usual scaffolding and screening, I had noticed while biking by that the work involved “energetische sanierung,” or energy retrofitting.

The Street-Side Energy Audit

Posted on January 6, 2014 by Erik North in Guest Blogs

When my wife and I bought our current house, one of the home’s appeals was that it was largely uninsulated. Given the choice between somewhat insulated and uninsulated, give me the blank slate every time.

We moved in in September, and because of a super-busy energy auditEnergy audit that also includes inspections and tests to assess moisture flow, combustion safety, thermal comfort, indoor air quality, and durability. season and the need to unpack, any desired home-improvement projects were temporarily back-burnered.

Open-Cell Spray Foam and Damp Roof Sheathing

Posted on January 3, 2014 by Martin Holladay, GBA Advisor in Musings of an Energy Nerd

Now that insulation contractors have been installing spray foam insulation on the underside of roof sheathingMaterial, usually plywood or oriented strand board (OSB), but sometimes wooden boards, installed on the exterior of wall studs, rafters, or roof trusses; siding or roofing installed on the sheathing—sometimes over strapping to create a rainscreen. for several years, we’re beginning to accumulate anecdotes and data on successful installations and failed installations. The anecdotes and data are enough to provide a few rules of thumb for designers and builders who want to install spray foam on the underside of roof sheathing.

More Wishes for 2014

Posted on January 2, 2014 by Alex Wilson in Energy Solutions

Last week I wrote about a handful of product introductions and improvements I’d like to see in the coming year. This week, I’ll focus on a different level of New Year’s wishes: not product-related, but trends and broader change.

An Update on the Pretty Good House — Part 2

Posted on December 31, 2013 by Christopher Briley in Green Architects' Lounge

Cocktails in hand, Phil and I pick up the conversation about the Pretty Good House. Be sure to check Part 1 of this episode for some of the basics and the origins of this nebulous building/design concept.

The Highlights:

A Great Anecdote: Phil tells a great anecdote that illustrates the need for the Pretty Good House Guidelines.

Installing Windows the Right Way

Posted on December 30, 2013 by Scott Gibson in Q&A Spotlight

Brian Beaulieu would seem to be well on his way to enjoying a high-performance house in southern Maine. The double-stud walls are 10 1/2 inches thick and insulated with mineral wool. The exterior 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. is the taped Zipwall system, backed up with airtight drywall on the interior for a second line of defense against air leakage.

Beaulieu has invested in top-quality tripled-glazed Intus windows suitable for 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. designs. And it's here that Beaulieu has run into a problem.

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