We always instruct the business/property managers to have the venue ready by the time of the scheduled session.
Any delay on their part of more than 15 minutes does not oblige you in any way to stay longer than planned in order to complete the session. We do not cover any extra time, so please contact us to inform us of the situation on site via chat (look for the blue chat bubble at the bottom right on our website) before deciding on your own (or at the business/property manager's suggestion) to stay for longer than planned on the shoot.