One of the biggest energy hogs for any building would be the lighting and the climate controls. I've seen varying amounts of integrations both in the US as well as abroad. I have to say, though, the Irish design and architecture do a great job of using their designs to reduce the consumption of energy for airconditioning and lighting. By leveraging open dynamic cooling, novel insulation methods, and available lights, the United States could reduce their consumption of energy.
One of the first things that I noticed when I walked into the Quinn School of Business was that the atrium was wide open... I mean WIDE open. The ceiling was transparent to let in as much light as possible - there were even trees freestanding on the ground floor. It gave the entire building a spacious, airy feel that limited the use of artificial light as much as possible. It was always bright and this allowed supplemental lighting by way of indirect light - it wasn't as harsh on the eyes at all. Take note, USA.
Where the two come together is another interesting thing that I've never seen anywhere but Ireland. At the top edge of a line of windows on the exterior of buildings, there is a grill arrangement with angled slats. These slats angle off the light depending on the sun's position in the day. It allows two different savings. First, by giving a shade to the window, there is no need to lower shades which would block out too much light and therefore require the use of lighting. The second is that by reducing the need to tint the glass, as is the custom in the states, colder climates such as Ireland will be able to utilize the natural convection heating and not need to turn on the heaters.
When it comes to design, besides the transparent ceilings and the like, there are a few design characteristics that Ireland just nails. The first was that shade above windows - that's great for reducing consumption. The second really noticeable and beautiful design feature is the use of what I would call buffer space inside windows. Basically one completely clear pane of glass is either outside the line of the building's walls or flush but then about a foot or two behind that is the interior pane. By creating an open buffer, a wall of air, between the structural glass, heating and cooling efficiency is greatly improved. It's similar to how double paned glass keeps windows from leaking heat but on a grander scale. Colder air in the shadows would be able to cool the heated air in the sunny parts to make for a temperate average temperature.
By combining technologies such as these with designs discussed here, I think that the United States could do a lot to reduce electricity consumption and ultimately the need for oil dependency. More to come this week!