Are Big4 audit people always in clients offices?

I was just wondering whether people starting out at the big4 in audit ever do audit work at the big4 firms office or whether they are usually at the client's office. Roughly what percentage of the actual technical work would be done in a clients office? 100%? Or is some work done at the big4 firms office as well?

I'm in school so I was wondering

I reckon it depends on many factors with the main ones being

- timing within the audit. If its busy season and you (probably will) need to ask the client loads of questions that need to be resolved within a short timeframe, it would always be better to be at their offices. They can't avoid you standing over their desks, but they can easily ignore emails!
In the early stages before you audit the final figures, where there will be less people on the team, you will most likely be in the office because questions can be answered later.
Also, it is inefficient for 1 auditor to have a whole audit room to themselves - rather, clients like auditors to have as little space as possible so if you have more than 30cm of space between you & the next person, then it is too much

- location of client. If the finance function is overseas, then it's unlikely that a audit junior will go (in my experience, but obviously there is the odd exception I've seen). They want to minimise the costs of performing the audit as much as possible, so in these instances emails usually suffice!

- general stuff to do in the office e.g. scaning / expenses / trainings/meetings so you will have the odd day here and there in the office.

For me, its been about 70:30 (Client : Office) & obviously the college time in my first 2 yrs (I am just finishing 2nd year now & coming up to the end of the 3 yr contract). Hope that helps