Waterproofing for wet areas is standard, you'll be given th certificate at handover.
I can definitely recommend eaves all around, sarking and double glazing. They all improve the insulation qualities of your home.
I agree with blackcat20. All those items will improve efficiency. I love our double glazing. 4 degrees overnight and our rooms don’t drop below 16 degrees by morning. Personally I would never build without eaves, as I think it looks awful. We went with a colorbond roof therefore had to have sarking. I don’t know much about it though.