The most recent blogs at Green Building Advisor

A Researcher Looks at Insulated Roof Assemblies

Posted on July 22, 2016 by Martin Holladay, GBA Advisor in Musings of an Energy Nerd

Kohta Ueno knows a lot about insulated roofs. As a researcher and engineer at Building Science Corporation in Westford, Massachusetts, Ueno has seen plenty of well-designed roofs, as well as plenty of rotten 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 a building science researcher like Ueno, rotten sheathing isn’t a disaster; it’s data.

Fannie Mae’s Financing for Solar is a Game Changer

Posted on July 21, 2016 by Anonymous in Guest Blogs

By LAURIE GUEVARA-STONE and JAMIE JOHNSON

Mortgage giant Fannie Mae just unlocked the lowest cost of capital for new 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. (PVPhotovoltaics. Generation of electricity directly from sunlight. A photovoltaic (PV) cell has no moving parts; electrons are energized by sunlight and result in current flow.) installations to date. This follows the recent decision of the Department of Housing and Urban Development (HUD) to finance new solar installations within a first mortgage transaction. HUD's decision is a potential game-changer for the solar industry, with the ability to bring about the next order-of-magnitude increase in solar installations.

The Third Time’s the Charm

Posted on July 19, 2016 by Carl Seville, GBA Advisor in Green Building Curmudgeon

After two failed attempts at building a new house, I’m finally ready to get started. My first plan, started in 2009, was shot down by the historic commission.

Mounting Baseboard Heaters Unconventionally

Posted on July 18, 2016 by Scott Gibson in Q&A Spotlight

Writing from Detroit, a Climate Zone 6 locale, Marlena Crows poses this question: Must electric baseboard heaters necessarily be installed at floor level, or can they be mounted higher on the wall and get an assist for heat distribution from a ceiling fan?

Comparing the Properties of Insulation Materials

Posted on July 15, 2016 by Martin Holladay, GBA Advisor in Musings of an Energy Nerd

We’ve all seen tables that list the R-valueMeasure of resistance to heat flow; the higher the R-value, the lower the heat loss. The inverse of U-factor. per inch for a variety of insulation types. These tables are handy, of course, but because old information is endlessly republished, in some cases long after the old information becomes obsolete, the tables are often flawed. Most authors make little effort to update these tables in light of the latest information from researchers.

Medical Group Warns of Health Threats from White LED Street Lights

Posted on July 14, 2016 by Richard Stevens in Guest Blogs

The American Medical Association (AMA) has just adopted an official policy statement about street lighting: cool it and dim it.

The statement, adopted unanimously at the AMA’s annual meeting in Chicago on June 14, comes in response to the rise of new 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. street lighting sweeping the country. An AMA committee issued guidelines on how communities can choose LED streetlights to “minimize potential harmful human health and environmental effects.”

From Superinsulation to Passive House, With a Trip Across the Pond

Posted on July 13, 2016 by Allison A. Bailes III, PhD, GBA Advisor in Building Science

In 2002, Katrin Klingenberg introduced the 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. program to North America when she built the Smith House in Urbana, Illinois. She had come to the U.S. from Germany, where she studied architecture and got involved with Passivhaus. But is this really where it all began?

Can the EDGE Green Building System Save the Planet?

Posted on July 12, 2016 by Stuart Kaplow in Guest Blogs

While Nepal is breathtaking, containing eight of the world’s ten tallest mountains, the country is landlocked to the north by China and to the south and east by India. It's a developing country with a low-income economy, ranked among the poorest of the 187 countries in the U.N. Human Development Index.

Writing this post from Nepal, I think that it seems appropriate to discuss EDGE.

CarMic House: Improving Indoor Air Quality

Posted on July 11, 2016 by Carri Beer and Michael Hindle in Guest Blogs

Editor's note: Carri Beer and Michael Hindle are renovating a 1954 house in Catonsville, Maryland. Hindle is a 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. Consultant and owner of Passive to Positive. Beer is a registered architect who has been practicing sustainable architecture for 18 years. She is an associate principal with Brennan+Company Architects. For a list of the couple's posts, see the sidebar below.

Construction in Cambodia

Posted on July 8, 2016 by Martin Holladay, GBA Advisor in Musings of an Energy Nerd

A few weeks ago, I accompanied my wife Karyn, who is a pediatrician, on a three-week trip to Cambodia. She volunteered her services at the Angkor Children's Hospital in Siem Reap, in response to a request from hospital administrators. The hospital invited her to Cambodia to provide two weeks of specialized medical training for the hospital staff.

Lucky me: I got to tag along.

Siem Reap is a bustling town in northwest Cambodia, only a few miles away from the world-famous temples of Angkor Wat.

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