GreenHomes has put together a simple tool, the “Interactive House“ to look at the potential to save energy in your home. 
This is NOT a model, and can’t provide you with detailed and recommendations or predictions about your home specifically. (That’s what a home assessment is for.) It’s meant to be a simple and fun tool. And in broad-brush terms, it can give you an idea of the areas to focus on and allow you to see how the savings interact in a typical home. It give also provide a quick gut-check on the level of savings to expect. If someone is claiming they’ll save you a lot more with a particular measure–say 50% energy savings for windows which is NOT a reasonable expectation for most homes–then this will raise a flag that you should dive into the weeds a bit, find out what assumptions and data they’re using to make that prediction for you, and validate (or not) the claims.
Thanks,
Mike
