I'd be thinking about doing something with those fences whist access is easy. Id be looking at adding gravel boards and using lesser height panels, thus allowing the ground levels to be uniform across the site.
Then build up to DPC and lay a concrete or slabbed path down the tricky side and back bit whilst access is good and before the walls go up.
Then build up to DPC and lay a concrete or slabbed path down the tricky side and back bit whilst access is good and before the walls go up.