Hi Dave,
When carrying out the survey of any premises, these are just some of the questions that should be asked, regarding the security aspect, most often the cleaning operatives will be the last person to leave the building, so blinds should be drawn, and all entry exit points (windows/doors/fire escapes etc), should, as a matter of course be checked.
However, you do indeed raise a valid point, after agreeing a specification and standard of cleaning to be attained, some clients then try to add on "extra's", within the industry this is known as "contract creep".
This can seriously damage your profit margin, your survey paperwork, and your questioning at survey time should be framed in such a way, to make this type of behaviour, next to impossible.
It is then, a simple process to explain to your client, that each "extra" task, has both a time and fiscal element. That way, you give the client a choice.
You should not, obviously, "load" the contract, so that you can give a low price at quote time, omitting tasks that your client has every right to expect, as standard, then add these tasks at a later date.
Regards,
Rob