Plastics restoration is completely different to giving them a quick wipe over to remove surface dirt so should be charged accordingly. How much you charge is up to the individual.Just remember that if you spend time bringing frames, sills, doors etc back to good condition on a first clean and you don't charge extra you could end up being out of pocket bigtime. Especially when you get some that change their mind (lie) and don't want a regular clean after all which can happen
right now I'm doing it traditional and I find PVC frames are not easy to clean. I been using CIF cream cleaner to get rid of tough stains and buildups, works pretty well actually. I'm charging £12 just for the front (3 bedroom terraced house) in East London but I'm starting to thinking I'm under charging. what do you think?