Does your home inspection report do anything more than state the obvious? Like saying that there is dampness in a particular wall, or that there is so much (in percentage) of moisture present. If that is all which is being said in your brief then it is a very average sort of reporting.
What the Client expects is something more – what is to be done about any issue, how long and how much it will cost? There will be more questions of this sort and if you have answered it all, only then will your report be of real value.
All this extra bit of work costs that much more and a discerning Client would be more than happy to pay for that much of additional effort.