When we clean uPVC windows, soffits, fascias and conservatories we don't just "spray-and-walk-away", we use only the best cleaning materials, recognised by the trade, and we gently use warm water so as not to cause damage. Then we wash down with surface finishers to give a shiny finish that will help resist future soiling; again - all within the price, no hidden extras!
You don't even need to be at home when we do the clean (though for conservatories we can get a more complete finish if someone is there to open and close the windows so that we can clean the window-shuts), and because we carry 500 litres of water there are many jobs that we can complete without even connecting to your water supply.