Outbuildings property boundaries

[Islatrin]

Please could someone help me. My next door neighbor recently built this outbuilding on his back garden. As per photographs it’s huge, there is countless nails sticking out on my side, it blocks out pretty much most of the sun now & looks terrible. The height is 2.40 meters, however I read somewhere if the hight is between 2.50 & 2.00 meters outbuildings must be at least 1 meter away from any property boundaries, does anyone know if that’s the law. I’m not wanting him to take it down, maybe lower the roof or move it. My daughter is disabled & as absolutely know sense of danger, the back garden was the only safe area for her to play in. I have to put the kitchen light on during the day because it blocks the sunlight out & it’s so unsightly It’s reduced me to tears many.