I still don't understand the design. If it's a weird angle to fit the boundary then you can't overhang the roof into the neighbour's airspace.
Redesign it so it's not weird! Stop trying to gain every possible square inch at all costs.
Angled corners on brickwork almost always look terrible. I built a nice 135 degree corner using special bricks. But everyday builders use standard bricks with horrible fillets of mortar, it always looks awful. I doubt you could even buy angled bricks in whatever weird angle this design needs.
Redesign it so it's not weird! Stop trying to gain every possible square inch at all costs.
Angled corners on brickwork almost always look terrible. I built a nice 135 degree corner using special bricks. But everyday builders use standard bricks with horrible fillets of mortar, it always looks awful. I doubt you could even buy angled bricks in whatever weird angle this design needs.

