ISO ratings are based on your fire department response times and I believe it also depends on the distance between you and your closest fire house. Feel free to call your fire department to get info. SWFD is 267-1298. (SWFD does not operate North of the bay.) They can send a letter to your insurance carrier relating to the above info. For the first time, my insurance carrier requested just that this year. Your fire department is here to help you so please do not hesitate to call and get information you and your insurance carrier will need. Good luck and please keep us posted.