Yes you can refi any type of property residential or commercial.   

Hi I am trying to purchase a residential property through my S Corp, if anyone has more information that would be extremely helpful 

Here's some to get started, and I'm sure people have better:* virtual work will migrate down the food chain of jobs, making internet/visual hookups more like a utility and possible differentiator for residential landlords*rental/business interruption insurance will evolve..more expensive and more comprehensive?

If you have a friend or family member (personal loan even) that you could borrow the funds from for 15-30 days, you could buy in cash and then execute a delayed financing under a residential loan immediately.

Whereas with the 4plex, I'd have to wait for the procession of the residential market.

Honestly, I don't think the residential real estate market will be hit that hard as a whole for any length of time. 

Likening non-paying residential tenants to thieves is what's judgmental.

I am located in IL and this is for a residential property. 

I'm about the clean it up and put some anti mold primer on it.I need to have an mold inspector certify it.

It may not even be feasible to increase the residential occupant load of the buildings based on how the subject buildings construction is classified, number of means of egress, widths of egress, etc etc etc, Yada, yada, yada...~ OR ~You could hire a Registered Architect who could provide you with a professional feasibility study and report regarding your modification proposal that would take the above factors into considerations and give you a sharper insight of what you can and cannot do.