In this, our final installment of articles on high efficiency homes, we will be looking at the builder's perspective on high efficiency homes. For this, we have spoken to Shaun Pardi of Envinity, a Pennsylvania contractor who focuses on sustainable construction, including high efficiency homebuilding. When asked about the current status of the market, Shaun noted that, while custom homebuilders are showing quite a bit of interest, the spec home market hasn't gone high efficiency yet. There is some movement in this area, however, and homebuyers are increasingly requesting a EnergyStar rating on homes they are considering.
Three Keys to a Happy High Efficiency Home:
When asked what are the key aspects of high efficiency construction, Shaun pointed out three main components, which from his perspective make a high efficiency home work. Readers will notice striking similarities to what was shared by high efficiency homeowner Bill Dripps in our last article.
First, insulation levels must be notably higher than in typical construction. Recommendations vary depending on location, but are often two to three times higher than standard practice. This would be unproductive overkill in normal buildings, but ends up working very well in high efficiency homes due to the other two key components.
Second, managing air infiltration and exfiltration must be part of the high efficiency home's design. This takes the form of active air exchange coupled with extremely rigorous sealing of the building envelope. Even something as seemingly innocuous as fastening exterior sheathing to stud walls must be carefully considered to make sure you are not creating pathways for air (and moisture) to travel unimpeded into and through the walls.
The third key component is high efficiency mechanical systems. The mechanical system is the "heart of fire" that provides the warmth and comfort to the home, and while the first two components of the design reduce the total heat load a great deal, improved efficiency of heating and cooling still reduces overall energy use (and costs) to a noticeable degree. Also, recent developments in heat pump technology have resulted in products that are noticeably more efficient than what was on the market only a few years ago. "It's amazing what can now be done" says Pardi, who is quite bullish on the latest generation of heating technology.
Who Will Build it?
While these three components are critical for a high efficiency home to function well, there is another important aspect that we haven't mentioned yet - the builder. Having a good builder involved with your project is critical to long term success of your high efficiency home. While a traditional home might look much the same as a high efficiency home, the skills and techniques involved in building a high efficiency home are not quite the same. Fortunately, finding a good builder isn't as challenging as it may have been in the past. A good high efficiency homebuilder should be "genuinely interested in the process," notes Pardi. The US EPA EnergyStar website and your local builders' association are good places to start.
What About Existing Construction?
This is all certainly very interesting. However, if you're interested in energy efficiency in the region, it overlooks one important point. The number of new homes being built is very small when compared to the number of existing homes in use today. "More people are renovating" than building new, says Pardi.
All of this raises the question of whether or not the large number of existing homes can be converted into high efficiency ones. The answer, it seems, is "not completely, but it's worth it to do what you can". Shaun says that it's relatively easy to reduce energy use of an existing home by 10-20% without running into significant challenges. This often comes in the form of improved insulation and controlling the most dramatic cracks and leaks. Improvements beyond that point are possible, but one must be very careful about issues such as moisture control, which aren't as easy to manage in an existing home when compared to new construction. "The weak point" says Shaun "is the windows". Not only are they a notoriously inefficient part of the home, it is extremely difficult to find cost effective ways to improve their performance. Decisions to upgrade windows still require a non-energy justification, such as comfort or aesthetics, before they can begin to make sense.
Should You Do Something?
Is your home in need of an energy upgrade, or maybe even replacement? One place to start is to check your home's performance using the "Home Energy Yardstick" too from the US Department of Energy. This self-serve online calculator lets you find out if your home is an energy hog or a watt miser, relative to similar sized homes in your area. If the results are not encouraging, the next step would be to have an energy audit done, in which an energy professional inspects your home and makes recommendations for cost effective upgrades.
Where does this all leave us? Probably the first thing to conclude is that, if you are considering building a new home, you owe it to yourself to consider going with a high efficiency design. They are increasingly common, and can be very attractive from a comfort, energy, and overall cost point of view. Second, if you live in a traditionally-built home, there are probably some aspects of high efficiency homebuilding that you can utilize to improve your home's performance. Lastly, as Shaun Pardi so aptly notes: "Energy efficiency doesn't have to be complicated or scary. A lot of it is common sense".