Hi Tim, Gary,
Gary yes I would normally charge half for the second clean, like I said currently 15p per sq ft is the minimum I charge for the initial clean, this would be on a basic property, in most cases I would go in a third time for the sparkle and like Tim said the property can in some cases need nearly as much time spending on it as the initial clean, but the main difference with the clean is that the windows should be ok.
In most cases the windows are the most time consuming job on the initial new build clean.
Regards
Paul