splashback from entryway roof rotting house

Hi, We live in new england and I can’t seem to find a solution to my issue hoping for help. We have a 2 story house and on the backside the metal roof is about 40′ high, the entrance to the basement is a regular door with an A frame metal roof, about 10′ high. the issue is with the rain coming off the upper roof and hitting the lower roof below, splattering a 12′ circle on the backside of the house. I just replaced the window that constantly gets soaked and the timbers were all rotten because of the splattering. I thought about putting a section of gutters on the upper roof but it doesnt have a steep pitch and snow/ice build up and curl around. Is there any type of anti-splatter gaurd or something like that so I dont have to replace the window/frame every couple years lol. Many Thanks -Chris
Replies
Gutters are the only thing I can think of.
How about a rain diverter. Something like this: