Rent a res 15k a week for a 60 by 60 privets res you will be getting 2 days you to make the res back Normal or you can rent for another week you get 7 days to build with Admin and 2 days to clean up your build or I will reset res Pm if interested
The wiki states: https://empireminecraft.com/wiki/storage-banks-and-loans/ Based off of this, I would say it is allowed. However, it isn't recommended, as it certainly presents many risks.
Is the res in a good location? What SMP is it on? Is the two days included in the seven day rental or do you have two days at the end of seven days to clean up?
