Vacant upon closing

[Michael Morin]

hopefully I will be starting to purchase my buy and holds soon. I say hopefully because it's all going to start when my primary home sells.

I was curious if it's common practice to require any place be vacant upon closing. I will be living in one side so that's a definite but I read lots of horror stories about tenants that have been carried over. 

Does asking for vacant upon closing hurt your offer? Any info on this would be appreciated.