Anna, We looked at SIP built house here in Texas a couple of years ago and the cost wasn't that bad. I think the good part about them is not only do they save energy but they go up really fast. Solar hot water heaters can be fairly expensive. Have you looked at some of the on demand hot water heaters. My son has two of them and they work quite well if you can run them off of gas or propane. Good luck with your house

In Dog Beers, I've had one.