Every year, the National Association of Homebuilders holds their big Green Building Conference in a different city. This year, Dr. Energy Saver™ reports on the NAHB’s GBC from Raleigh, NC. This is the first in a series of reports from the conference.
Building Green: Passive House Adventures
The temperature was mild when I arrived in Raleigh Thursday afternoon. But today then it was back to the hot, humid weather this region is famous for. In New England, where I live, our biggest energy expenditures come in wintertime. Down here, air conditioning is what consumes the most electricity. So how can buildings stay cool without spinning the electric meter so fast? Stay tuned and I’ll fill you in. I’m looking forward to this year’s green building conference because I want to catch the buzz among building industry professionals who are attending the conference and see what’s new in the way of insulation, air-sealing, radiant barriers, HVAC equipment, solar energy and all the other factors that can contribute to better home energy performance. Remember folks, buildings here in the U.S. are responsible for almost half of our greenhouse gas emissions and over 75% of all the electricity we generate. At Dr. Energy Saver, our mission is to utilize the most up-to-date technology to make energy savings accessible and affordable for anyone who’s interested in improving energy efficiency at home.
In advance of the conference, I got an exclusive early look at a new Passive House that’s being built in Chapel Hill by Casey Shaw and Anchorage Building Corp. What’s a Passive House? Despite the mild-mannered name, a Passive House is pretty exciting in terms of energy performance. A Passive House is a comprehensive system of superinsulation, airtight construction and other features that can cut heating and cooling costs by up to 90% compared to a conventional house.
The initial research on the Passive House was done in Europe, but today there’s growing interest in applying this technology here in the U.S. Although a Passive House can be built in just about any style, you can count on a superinsulated building shell. The photos I took at the jobsite this morning show thick walls that combine concrete slabs with 7 in. of rigid foam insulation. The slabs are precast at a factory with openings for windows and doors already made. A big crane hoists the slabs into position, and then they’re bolted together. This construction technique eliminates the thermal bridging that exists in wood-framed walls, and gets the house enclosed much faster. The builder says I can come back on Tuesday morning to see the second level slabs being hoisted into place, so stay tuned for photos that show this dramatic construction technique. In between now and then, I’ll be reporting on new products and other stuff at the green building conference.
Tim Snyder
