1) INSULATION Most houses have traditionally used some variant of fiberglass insulation in the past. A growing trend now is in the direction of "Spray Foam" insulation, which is what you see in the next few pictures. I've just completed having the entire house blown with spray-foam and the process blew me away (pun fully intended!). There were guys running around in head-to-toe white astronaut suits with full face masks and head gear making an incredible mess out of the place.



http://www.biobased.net/homeowners/index.php .
2) WATER
If you're like an overwhelming majority of homeowners in the U.S., you probably have a hot water tank in your house somewhere. What does a hot-water tank do? - - - It STORES hot water for your convenient use when you want a shave, shower, or whatever. Since it STORES hot water, that means it is CONSTANTLY maintaining a fairly large supply of water. That means the heating element in your hot water tank (gas or electric) is using energy around the clock (like when nobody's home), every day (even when you're away for 2 weeks at Grandma's house) to keep that water hot for you when you're ready to use it. My new house will NOT have a hot water tank. It will use an IID Gas "ON-DEMAND" Tankless water heating system. This is very different than a tank, highly Energy Star compliant, and very energy efficient because it ONLY heats the water WHEN YOU NEED IT, it does NOT maintain a tankfull of hot water. It also NEVER RUNS OUT of hot water because it is a continuous solution when in use, heating the water as it passes thru the unit, and it uses NO energy to heat hot water when you aren't using hot water. That's huge. Again, since you're using less energy in the long run with this system, it is considered very "Green". Yes, a little more investment up front than a traditional tank, but a large return after the relatively short 1 year ROI on the additional cost. http://www.energysavers.gov/your_home/water_heating/index.cfm/mytopic=12820
3) WINDOWS and DOORS
Since this is turning into a rather lengthy Blog Post, I'll shorten these final two discussions. Windows are huge contributors to radiant heat in your house, so Energy Star requires windows that reduce the amount of ultra-violet light that comes in and heats your house through passive radiation.
In southern climates, it's very substantial. High end UV reduction windows use Argon Gas as a filter between the insulated multi-paneled windows. The next level down, which is still Energy Star compliant simply uses what's called "Low-E" glass, which is pre-treated in production of the glass to limit ultra-violet radiation. That's what I have, along whith "Therma-Tru" insulated entrance doors - also Energy Star compliant.
4) APPLIANCES
The final element in my Energy Star house considered were the appliances. Ever noticed the "Energy Star" seal on some dishwashers, ovens, and ranges/cooktops? I've decided to use a rather un-common but HIGHLY rated brand of Dishwasher and in-wall Oven, called "FISHER-PAYKEN". These are near-commercial grade products, and the real saver here is what they call a "Dish Drawer", in lieu of a dishwasher. It slides out like a drawer for easy loading/unloading, and is very quiet and uses a longer wash cycle to reduce the energy needed to wash the dishes. The FP Oven is highly insulated and heats very evenly and is also Energy Star compliant.
The GREEN BONUS: Even though most of these items are more costly than their less "Green" counterparts, the government provides substantial "Energy Star" rebates, refunds, and tax credits for using them, making the ROI's, payback periods, and additional costs even smaller! In the long run, these are simply smart choices if you ask me that you won't normally find in most homes because of the Builder Cost equation. So far, I think they're very strategic choices that will put money back in my pocket in energy savings year after year.