I've been asked to put in a quote for this job, I'd like to win this but have no experience of buildings this size. First off what price do you think I should be going in at to stand a chance of winning? I do have a price written down but I might well be way off the mark. There are a few velux windows not in the pics and it will outside clean only. Second how long should this take me? Third how much water will I be expected to use?