Quoting is not an exact science.  Since we do not do in-home estimates, we do our best to schedule the right amount of time for each cleaning based on the information you provide about the size and condition of your home. And, we get it right most of the time. Once in your home, if we do not feel we will be able to complete the job in the amount of time scheduled, our office will call you immediately.  At that time you can either add additional time at our normal hourly rate or provide us a list of priorities.