No answer.
While we're waiting, Slip has raised an interesting point, about dust sheets and clearing up.
Presumably this house was occupied, and full of furniture and belongings.
Sometimes an electrician will just use one dust sheet, directly below where he is working, and nowhere else.
Ideally everything should be covered up, even when doing the smallest of chases, but you might need 50 dust sheets.
The problem with occupied homes is the amount of clutter in them. For instance, a home could be full of china ornaments, bottles of wine and other delicate things. You can't put a dust sheet over things like that, because if the dust sheet should slide, it's goodnight vienna.
I have no idea what was agreed with Slip regarding the use of dust sheets. Also have no idea what clean up programme was adopted.
Hopefully we will get more details from Slip, but it has been of interest to me what customers really think of the aftermath we leave, even though we do our best to clean up.