Up to 1m without engineering. Built with drainage behind, finished clean at the top, and tied into whatever's stepping up to it.
Walls fail two ways. Water pressure builds up behind, or the base wasn't right. We dig it deep, drain it properly, and lay the base on compacted aggregate.
Most walls under 600mm we quote from photos. Anything taller. We'll come and look.
Footing trenched, compacted aggregate base, level confirmed before the first course lands.
Wall built course by course. Aggie line and filter cloth behind. Backfilled progressively.
Capping fitted, off-cuts to the tip, site swept. Photos if you want them.