Much of this depends on your home and where it is located. I am currently ditching my old oil burning furnace and going through the Community Powerworks Program. I get rebates and low cost loans to not only put in an electric mini split heat pump, but they will give me a break on insulating my old home as well. I look at the whole picture not just the heat source, but keeping the heat in once it's there.
A short answer to your question would be smart design including placement on the lot, passive solar, attention to the building envelope and much more. As a retrofit I believe an electric heat pump in the way to go. That way you will be ahead of the game when renewable energy is more common. They have been in Asia and Europe for a long time. If you want to get more ideas I suggest you check out the NW Green Home Tour on April 27th in the Seattle Area. It's a free tour where you will get to see these concepts in person. Just look it up online.... more
Washer and Dryer are usually not included in the sales of homes, so you could also consider how much you like these and plan on keeping them when you move. As far as an investment. In a year these are going to simply be "Used appliances" and not really be considered an upgrade or improvement.