How to increase Sheltered area on a build with a high roof, with large open windows. *if you have a fully walled structure please ignore. How -> You can hide roofing around the edge of the structure in the floor above. The 45 shelter calculation from the player head is resolved closer to edge.

*only applies to an open structure. Walls tall enough to intersect the 45 degree line achieve the same result. This only apples to open large windows. The image shows the 45 degree beams from the 2 roof lines. Close to the hearth in the middle is the shelter resolution of the upper roof. At RHS of the player is the 45 degree lines for the lower roof. The wood floor, on the stone work, highlights the usable shelter from just roofing the RHS floor. This can be added just above your windows for an increase of area. In just that area. For scale and reference the timber floor is 6m above the stone. The upper roof is 4m above that. 10m total height.

45 degree beams show the difference in sheltered buff. The timber floor shows the increase of usable sheltered area by adding just 3 sections of roof, In the floor 26 degree double roof fits in a half wall hollow. Adding an outer edge of roof increases it a little more.