Thanks Woody, I was concerned about inducing lateral loads in the walls due to movement.
Yes just a polycarbonate roof, the unsupported length is only about a metre.
I’m building a lean to between two houses and have run horizontal ties on the fence posts between both houses (3x2) that will act as the base for 4 off the 8 rafters on each pitch. Is it safe structurally to join the outside walls of 2 houses?
thanks