The most recent blogs at Green Building Advisor

Wrapping an Older House with Rock Wool Insulation

Posted on May 14, 2013 by Mark Yanowitz in Guest Blogs

When I first met Chris Gleba and Kris Erickson in December 2011 to discuss their plans for a deep energy retrofit, Chris told me that he had been remodeling his modest two-bedroom house in Lowell, Massachusetts, for over ten years. He had painstakingly rewired and re-plumbed the house and had made energy efficiency improvements (including the installation of a high-efficiency natural gas boiler and radiant in-floor heating). He had also devoted much sweat equity towards upgrading the interior finishes of the kitchen and baths.

Self-Professed Air Flow Expert Gets Hosed

Posted on May 13, 2013 by Carl Seville in Green Building Curmudgeon

Among the multitude of sessions at the ACI conference in Denver recently (a total of at least 180 sessions by my count), there was a very interesting half-day workshop on airflow testing hosted by Bruce Manclark and Paul Francisco. Their setup included simulated HVAC(Heating, ventilation, and air conditioning). Collectively, the mechanical systems that heat, ventilate, and cool a building. ducts of various shapes and sizes, and they used a Minneapolis Duct BlasterCalibrated air-flow measurement system developed to test the airtightness of forced-air duct systems. All outlets for the duct system, except for the one attached to the duct blaster, are sealed off and the system is either pressurized or depressurized; the work needed by the fan to maintain a given pressure difference provides a measure of duct leakage. to provide air flow to test various measurement tools.

Passivhaus Buildings Don’t Heat Themselves

Posted on May 10, 2013 by Martin Holladay in Musings of an Energy Nerd

For years, the English-language website of the Passivhaus Institut in Germany provided this definition: “A 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. is a building in which a comfortable interior climate can be maintained without active heating and cooling systems. The house heats and cools itself, hence ‘passive.’”

A Good Time for Energy Audits and Weatherization

Posted on May 9, 2013 by Alex Wilson in Energy Solutions

Wait a second. Spring has barely sprung, and you’re saying we need to start thinking about energy audits already? What’s up with that?

There are several reasons why now is a good time not only to focus on energy auditing and weatherization work — not only for your clients, but also for your own home.

A PhD and an Architect Build a Net-Zero Home

Posted on May 8, 2013 by Allison A. Bailes III, PhD in Building Science

Amy Musser has a PhD in Architectural Engineering and, like me, used to be a college professor. Her husband, Matthew Vande, is an architect with an MS in Architectural Engineering. He is also a treehugger (see the black and white photo below). Together, they founded Vandemusser Design, a firm that provides green design, certification, and consulting.

After a Bumpy Start, a Passivhaus Success Story

Posted on May 7, 2013 by veronique leblanc in Guest Blogs

In 2006, when we bought our house in Mamaroneck, New York, it was all about location: views on Mamaroneck Harbor, a south-facing orientation, proximity to the train station and the village’s main shopping street, and the ability to have a decent sailboat moored in deep water across the street and winterized at the shipyard next door.

How to Deal With a Vapor Barrier Edict

Posted on May 6, 2013 by Scott Gibson in Q&A Spotlight

Christopher Solar had a simple plan for an addition to his Ottawa home. The one-room structure would have a shed-style roof with a cathedral ceiling and vertical board siding. Solar liked a wall assembly he'd read about at GreenBuildingAdvisor, which consists of exterior foam, batt or blown insulation in the stud cavities and airtight drywall on the interior. An interior polyethylene vapor retarder never entered the picture.

And that's where his story gets complicated.

All About Thermal Mass

Posted on May 3, 2013 by Martin Holladay in Musings of an Energy Nerd

UPDATED on December 4, 2013 with a citation of recent research findings.

What’s the deal with thermal mass? Since manufacturers of materials that incorporate concrete often exaggerate the benefits of thermal mass, it’s easy to get cynical and conclude that the buzz around thermal mass is all hype. But in many climates, it’s actually useful to have a lot of thermal mass inside your house. Just keep in mind that thermal mass may not be as beneficial as its boosters pretend.

What’s Different About Unity Homes?

Posted on May 2, 2013 by Alex Wilson in Energy Solutions

In my blog last week, I provided a little background on Tedd Benson and his evolution that ledLight-emitting diode. Illumination technology that produces light by running electrical current through a semiconductor diode. LED lamps are much longer lasting and much more energy efficient than incandescent lamps; unlike fluorescent lamps, LED lamps do not contain mercury and can be readily dimmed. him to found Unity Homes. This week, I’ll describe some of the features that set Unity Homes apart from both standard home construction and other panelized and manufactured home production.

All About Climate Zones

Posted on May 1, 2013 by Allison A. Bailes III, PhD in Building Science

One of the fundamental principles of building science is that buildings must be suited to their climate. When they're not, problems can ensue. Maybe it's just that they're not as efficient as they should be. Maybe it's worse.

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