It's not the height Dave but the ( assuming it is ) wrap around gutter on the corner tower and looking at the area further back which appears to go right across the lower roof.
To access these properly you need to be right up there, and all the roofs looked pitched.
You could hire a vac from omni vac, there should be enough in the job price to cover the hire of a picker ( 250 for a day with operator ) and the vac even a really good wedge to buy one if you desire
Off now to gutter clear myself

Ruddy town centre work...
Darran