Google for the MA Mechanical Code and see what it says regarding requirements for distance to combustible materials. I am not aware of any rule specifically regarding a window - except the potential of trim that would be considered combustible. By freestanding are you talking about a 30" or 36" range that has the backsplash with the controls on them or are you talking about a pro/commercial style range? If you look up the detail specifications and installation instructions for your range model, it will tell you about clearances required by the manufacturer.

just a 30" range with the backsplash controls. i'll try to find the code, i've been looking for a while.

If it is a standard freestanding 30" range with controls on the backsplash, then I think the backsplash would be high enough so that you would not have any code issues - unless MA is just way over board on requirements.

The manufacturers spec will specify clearances on all sides. Typically 18" above and sides can be flush since heat and flame go up. The material over the cooktop must be non-combustible. Some plumbing inspectors will consider a light rail that hangs slightly below the bottom of upper cabinets that are 18" above the cooktop in violation and will tell you to remove it.

Hey Daniel. Curious what you ended up doing? In the same situation. Thx