Shar, this is a great question for an insurance agent. There are a lot of factors involved with insurance. For example, how much would the property cost to rebuild if the house was to burn down? Not too crazy if you are buying a new house, but some of these historical homes I have sold are almost double of what my buyers are purchasing the home for. That makes the rate kind of high.
The insurance agent will need to know square footage and all sorts of information that you usually can find right on the listing card that you get from your real estate agent. Year built etc. I highly suggest getting in contact with a few different insurance agents and see where you can get your best deal. Just be sure you are comparing apples to apples.
I hope this information helps! Best Wishes to you!