As Labbe highlights in his article, complexity of design is most often a direct adversary of efficiency. This is clearly seen in European countries, where two decades of considerably high utility rates have led to a strong trend toward minimalist design and super efficiency. Compare this with the United States, where the current trend is to design larger homes (when able), often with deeply inefficient layouts. Whether we understand this or not, over-complicated architecture, and the concessions that are made to accommodate the attendant inventions of extra space, often directly impact the overall environment and comfort factor of our homes.
As an example of this phenomena, Green Building Advisor highlights all of the extra work needed to create bump-outs, in order to accommodate interior furnishings, as opposed to bump-ins. As a general rule, we love to see clean lines filling the interior of our homes, yet in many cases, the concessions involved negatively impact the functionality of a building. In order to highlight this, Labbe points out several disrupted HVAC runs in the home he uses as an example. Awkward corners and workarounds may seem unassuming when observed, yet each 45° elbow can result in 10 feet of equivalent duct resistance added to the air flow.
Ducts can also sometimes be placed against outside walls or corners, exposing them to the effects of exterior climate shifts, and vastly mitigating their effectiveness. In a forced-air system, engaging in this poor design practice will lead to conditioned air that has lost its pressure and temperature as it is moved upstairs, directly undermining the ability of the system to function. If your bedroom is on the second floor, you'll understand the long term effects of this design flaw very quickly.
There are a variety of other common design factors that can adversely effect the efficiency of your home as it is being constructed. Tight side attics and unusual dormers are prime candidates for poor insulation, simply because there is often little incentive to perform flawless work in these regions. This is, of course, where a trusted and reputable contractor comes in handy, but the work in these spaces is often difficult to do well. Their restricted space ensures as well that they won't be visited or inhabited often after construction is finished.
Larger homes require increased structural stability, and while added beams and columns usually fly past a homeowners attention as a necessary part of construction, their placement against outside walls can lead to the creation of thermal bridges. These areas represent a penetration of your home's insulation by a conductive, non-protected element, and can be directly responsible for moving heat or cold through the building's thermal envelope. Particularly in harsher climates that tend toward weather extremes, like the Northeast or Deep South, thermal bridges can be major hurdles in the establishment of an efficient home, incurring repetitive costs over the long-term.
Factors that can be assessed during the design phase of home construction will impact not only your energy consumption, but the interior climate and comfort level of your home. Keeping it simple in just a few key places can often lead to fewer headaches down the road, as problems identified in design are often easier to fix than after construction is finished. Spending a little extra time with your architect, and asking the right questions, is definitely worth the added effort.