Metal cladding of industrial unit

Hi chaps, 

Been asked to clean some cladding, just wanted to make sure my method and pricing is OK? 

8m high,  100m long, light soiling.

I was going to just pressure wash it with the terrible  fibre glass telescopic pressure washing pole I bought, but thought maybe if I applied a weak hypo / ubik solution I could just do a lower pressure rinse afterwards.   I save some water and it's more useable at low pressure.

£350 for a short day as I'd have to do the windows again afterwards,  what do you think?

I personally would softwashing it or spray with virosol and do it wfp we do lots like this , I tryed pressurewashing years ago and was never happy with the results