If you have a full round it isn't possible anyway, and there are always variables that will delay you.
Sick days, foul weather, dark nights, lazy days, late starts, holidays and so on.
I'm full up with work as it is, I couldn't get earlier if I wanted to, and as alex says, if you have a lot of commercial work then much of it will be for a set amount of cleans per year.
Though I've never really had a problem with turning up a day or 2 early when the occaasion has arose.
But I'm not sure I believe figure of over a grand a week and still being able to get the work done in even less time than before!
And with the figures quoted, you will have to be vat registered.
Presumably this lad is also employed correctly? Employers liability, taxed, employers NI and so on??
Ian