When a vault construction is completed do you get to choose where the vaultkeeper goes or is it always in the back corner?

If its always the same place, im sure many know already but to inform the others who dont, you can access the vaultkeeper from outside if you stand against the wall in that back corner (in my experience anyway), can make life alot easier especially when building on plots around the vault, it can be alot quicker than having to walk all the way in.