in the end I decided to use plywood, rather than cedar, to cover the corner post – mainly because I had a piece of marine plywood to hand and if it ends up looking terrible I will have only wasted £10 on materials. Besides I am getting impatient to be done with the exterior and start work on the inside.

corner post covered in plywood

obviously needs to be filled and painted to match the doors, but I think it will look okay.