What is a good rule to decide if I should form a new entity for a new property purchase?

[Anna Sam]

I have a few properties in one LLC and am in the process of purchasing an 8 unit also in it. Looking for other properties as well.
Just wondering what would be a good way to figure out if a new property needs a new entity? I am thinking 8 plex or more new entity would be good... please share your thoughts.

Also, more entities would be annual fees, book keeping expenses, accounting and IRS filing accountant expenses etc. So wanted to get an idea.

Please share your thoughts