Guest Blogs

In days of yore, buildings were designed and built by master builders. These were people who spent their whole lives learning about buildings by creating them – from idea to reality – working side by side with others, many of whom who had more experience than they did. That’s how they eventually achieved mastery. Practice, repetition, and observation of everything to do with the building’s creation.

Recently, I wrote a little article about the stack effect to explain that the flow of air and heat is upward in winter but downward in summer. Turns out, the stack effect is a hot topic. That article has gotten 25 comments so far. When I posted it to the RESNET BPI group on LinkedIn, it got another 22 comments.

Energy Star. LEED. Passivhaus. There are many programs with different metrics for determining how green your home is. But what elements of green building are important to you when designing and building a home?

One of the great ironies in construction (I bet you didn’t even know that construction could be ironic) is that Cape Cod style houses perform pretty poorly on Cape Cod. The year-round sea breezes wash right through a Cape building frame, making them chilly and uncomfortable in the winter months.

How did Cape Cod style houses (which perform not-so-great in the winter) become popular in New England? Maybe the name was a marketing scheme? And how can we address the air leakage and heat loss issues to make Capes more comfortable?

During the last month we’ve had a very stimulating conversation going about design – and how some important design opportunities for improving energy performance are often overlooked, and why. The dialogue started here and, thanks to fellow GBAGreenBuildingAdvisor.com Advisor Bruce King, continued on Facebook.

Now to continue the fun, we’re going to look at CODE – specifically, the energy code – and its role in high-performance and net-zero energyProducing as much energy on an annual basis as one consumes on site, usually with renewable energy sources such as photovoltaics or small-scale wind turbines. homes.

After a few false starts, the International Code Council (the code writing body for the U.S.) finally prevailed with the new International Green Construction Code, to be available in Spring 2012. Already there is media spin about the wonderful leadership shown by the U.S. in setting the example by providing such a code. Hoorah for the U.S.! I think…

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 U.S. (PHIUS) has banned the use of spray polyurethane foam (SPF) with high global warming potential (GWP). The discussion on high GWP insulation was elevated in an excellent piece, “Avoiding the Global Warming Impact of Insulation,” written by Alex Wilson, the executive editor of Environmental Building News.

During Passivhaus training last year, it was stated that this could potentially be coming down the pipeline – so we weren’t surprised to see this pending regulation.

The photo shows an unvented crawl space in a cold climate. The home was built in 1885. This crawl space is attached to an adjacent concrete-floored basement. The foundation walls are made of mortared limestone.

Even in the small area captured in the photo, there are a number of problems that compromise energy efficiency, building durability, and life safety.

Next week, we will post the answers that a Building America team, NorthernStar, came up with.

I'm embarrassed to admit it, but yes, that photo shows the gas furnace and water heater in my condo. (I used to live in a very green SIP home that I built, but that's another story.) It's an 80 AFUEAnnual Fuel Utilization Efficiency. Widely-used measure of the fuel efficiency of a heating system that accounts for start-up, cool-down, and other operating losses that occur during real-life operation. AFUE is always lower than combustion efficiency. Furnaces sold in the United States must have a minimum AFUE of 78%. High ratings indicate more efficient equipment. (80% efficient) furnace and natural draft water heater.

Working at Home Energy magazine would seem to have prepared me for having an energy-efficiency retrofit done on my own home, or at least to ask all the right questions. But Murphy’s Law intruded nevertheless, and you may learn from my experience.