I used to work for a cleaning company, doing private houses, offices etc. I think they quoted per hour,but then that particular house/business had a set number of hours it had to be cleaned in. So for e.g. I was responsible for cleaning 5 businesses after hours- 2 during the week and 3 on the weekend. It was worked out so that everything that needed to be done (i.e. vacuuming, wiping over desks, cleaning the toilet/kitchen area etc) all fit into that time frame, so depending on the size of the business (floor space, number of toilets/size of kitchen etc) determined how long we would be there cleaning for, and therefore how much they paid.

I think they were charged roughly ~$35/hr, could have been more...I know as staff we were paid about $20/hr which is the award wage. Also, the first clean or couple of cleans you do may take a little longer, just to get things up to scratch (you might have to spend a little extra time getting down cob webs or wiping down cupboard doors in the kitchen area, or those other little things that just gradually build up over time), so might be worth mentioning that the first couple of cleans *may* take a little bit longer, but after that it should take *x* amount of time each week (also bear in mind that the less frequently it is cleaned, the longer you'll have to spend there...so two places the same size, one gets done fortnightly, one gets done weekly, the fortnightly one you may have to spend 1 1/2 hours there, whereas you may only have to spend 1 hour/45 mins at the place cleaned weekly).

HTH!!