The most recent blogs at Green Building Advisor

All About U-Factor

Posted on May 5, 2017 by Martin Holladay in Musings of an Energy Nerd

The familiar NFRC sticker found on most new windows sold in the U.S. includes a number in the upper left-hand box labeled “U-factor.” For many homeowners and builders, an encounter with this sticker represents their first exposure to U-factor.

Once people understand that a window has a U-factor, they might learn that walls and ceilings can have a U-factor, too. At that point, confusion may begin.

Toronto Passive: High-Efficiency Lighting

Posted on May 4, 2017 by Lyndon Than in Guest Blogs

Editor's Note: Lyndon Than is a professional engineer and 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 who took a year off from work to design and build a home with his wife Phi in North York, a district of Toronto, Ontario. A list of Lyndon's previous blogs at GBAGreenBuildingAdvisor.com appears in the sidebar below. For more, you can follow his blog, Passive House Toronto. This post originally appeared in November 2014.

Large-Scale Solar Power Is Spreading Across the U.S.

Posted on May 3, 2017 by Cheryl Katz in Guest Blogs

This article was originally published at Yale Environment 360 and is reprinted here with permission.

Airport House: Choosing and Installing an ERV

Posted on May 2, 2017 by Reid Baldwin in Guest Blogs

Editor’s note: This is one of a series of guest blogs by Reid Baldwin about the construction of his house in Linden, Michigan. For a list of previous blog posts on GBAGreenBuildingAdvisor.com by Reid Baldwin, see the “Related Articles” sidebar below. You can read his entire blog here.

Tackling an Energy Remodel in New Hampshire

Posted on May 1, 2017 by Scott Gibson in Q&A Spotlight

From the sound of it, Ben Balcombe is about to buy a house built like many others in New England in the 1980s: 2x6 walls (presumably insulated with fiberglass batt insulationInsulation, usually of fiberglass or mineral wool and often faced with paper, typically installed between studs in walls and between joists in ceiling cavities. Correct installation is crucial to performance. ), double-pane windows, baseboard hydronic heat linked to an oil-fired boiler, and vinylCommon term for polyvinyl chloride (PVC). In chemistry, vinyl refers to a carbon-and-hydrogen group (H2C=CH–) that attaches to another functional group, such as chlorine (vinyl chloride) or acetate (vinyl acetate). siding. The house is in southern New Hampshire in Climate Zone 5.

Balcombe plans to renovate the house in phases. He'd launch a kitchen and bath remodel "as soon as we get the keys," with other upgrades to follow.

Revisiting Net Zero Energy

Posted on April 28, 2017 by Martin Holladay in Musings of an Energy Nerd

An 6-kW 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.) system can be installed for about $18,000 in many U.S. locations. With a 30% federal tax credit, the system costs the homeowner only $12,600 — or even less if utility or state rebates are available.

This 6-kW system will produce about 8,000 kWh per year in Boston (worth about $1,600) or 10,300 kWh per year in Phoenix (worth about $1,230). That’s a lot of electricity.

The Energy Conservatory’s New Blower Door Kit

Posted on April 27, 2017 by Peter Yost in Building Science

I don’t do blower door work every day, but I do enough of it to appreciate the attention to detail that The Energy Conservatory (TEC) built into its new blower door kit. The kit features a digital pressure and air flow gauge, the DG1000.

Questions to Ask Your Prospective Builder

Posted on April 26, 2017 by Allison A. Bailes III, PhD in Building Science

You're having your dream house built. You're into the design phase, working with an architect or looking through collections of house plans. You're doing your homework, trying to find out how to ensure you get a top quality house. And that's when you run into all this stuff about building science, high performance homes, HVAC(Heating, ventilation, and air conditioning). Collectively, the mechanical systems that heat, ventilate, and cool a building. design, blower door testing, and the like. Now you're hooked.

A Forgotten Tool to Solve the Housing Crisis

Posted on April 25, 2017 by David Goldstein in Guest Blogs

“The California housing crisis is even worse than we thought… California is the hardest state in the nation for people to buy their first home.

"Since first-time home buyers are overwhelmingly younger people, the long-term results will have an enormous impact on the economic prospects of the next generation …”

Air Sealing and Insulation in the ProHOME

Posted on April 24, 2017 by Mike Guertin in Guest Blogs

Editor's note: This post originally was published as part of the ProHOME series at Fine Homebuilding magazine. Mike Guertin, an editorial adviser at the magazine, is building the house in East Greenwich, Rhode Island.

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