Beverly actually has very few historic districts. One thing to keep in mind is that the Historic Commission has a one year demolition delay by-law. This helps prevent developers from taking down historic structures just because they are in the way. Often another solution can be found, or even the building in question can be moved to another site.
Absolutely Visit the historic commission in Beverly, Some towns have different restrictions, but all historic commissions have the information you need, IE... must looks remain the same? No Visible from the street additions?? type of material to color of the exterior. I wish you the very best in your search at the historic commission