Guest Blogs

The superinsulated home that I designed and built for my family of three in Greenfield, Massachusetts has been comfortable for the entire year and serves as an example of successful design for our climate. We moved in to our new home in February 2012.

Modest in size, our home measures 26 feet by 32 feet and has 1,500 square feet of living space, with two full floors plus a partial third floor tucked into the slopes of the cathedral ceiling. In order to decrease the overall volume while maximizing south-facing exposure, we chose a saltbox shape.

If you are ever suffering from insomnia, call me, and I will tell you all I learned about WUFI-Passive. It is the blessing (or curse?) of geekdom 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. me enroll in a three-day-long WUFI-Passive training class (sponsored by PHIUS — the 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. Institute of the United States) in downtown Chicago in early April.

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.

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.

Home energy audits in cold, northern climates are very different from those in hot climates. Different regions of the country have different types of housing stock, and there are regional variations in insulation methods and mechanical systems. In older houses, the type of weatherization work that has been performed varies greatly from region to region.

So the issues and energy priorities of northern houses are different from those of southern houses.

Construction projects are becoming more complex, with increasing levels of regulations, more product choices, and higher performance expectations. And there are so many more ways of getting bombarded with information — e-mail, text, voice-mail — that we get swept up into survival mode of responding to the bits of info as it comes along.

But the danger of this multi-tasking is that it doesn’t really work: you lose sight of the big picture (only seeing one piece of the elephant), and there is really no one who has a handle on the whole situation.

One thing that sets my teeth on edge as an energy auditor is when folks assume that a new home won’t have energy problems or be inefficient. A friend recently mentioned that weatherization and efficiency work must have a great market with Maine’s old housing stock but would be pointless in new homes. Commence ripping out hair.

Like wind washing, thermal bridgingHeat flow that occurs across more conductive components in an otherwise well-insulated material, resulting in disproportionately significant heat loss. For example, steel studs in an insulated wall dramatically reduce the overall energy performance of the wall, because of thermal bridging through the steel. is something folks mention all the time during audits (meaning they never ask about it). But what is thermal bridging, and why do I keep bringing it up when my customers just want new windows?

To understand thermal bridging, you need to understand your home’s wall assembly and the various materials used in its construction.

[Editor’s note: Liz Johndrow is a natural builder who specializes in the use of cob, strawbale, adobe, earthbag, and earthen plasters. During the winter months, she volunteers in Nicaragua, where she works with villagers, especially women, on construction projects in Sabana Grande, Totgalpa. What follows is a sample of Johndrow’s blog entries written from Nicaragua. You can learn more about her work at her website, Earthen Endeavors.]

Each month in Portland, Maine, a group of building professionals gathers for an evening of serious Building Science banter. The topic is either focused on a specific aspect of building science or opens up a lively discussion of what a Pretty Good House (PGH) would do in our cold climate of Maine. (For more information on the Building Science Discussion Group in Maine, check out the links in the "Related Articles" box, below.)