Dai,
Before you give a price, tell them you don't and won't work on a 'as and when basis'.
Tell 'em straight you only work on an agreed interval basis; even if that's an every-three-month or quarterly basis.
It does matter, and without agreeing to your terms; you won't quote.
If they don't agree, you haven't lost anything, since do you really want to clean a property that's only done once-a-year? And not only that; having done 'request' jobs; you generally lose them to other window cleaners anyway; since you don't have a chance to build up a repitoire with them.
Ian_Giles took a 100 quid job from us, which we did on demand, and he's charging them 120 quid and has a set cleaning frequency with them.
Why?
'cos they must've lost our details; so they asked him. The receptionist used to phone us to clean; maybe she moved on?
I promise you it wasn't from our quality of work. We used to do a good job!
