I oversee the marketing department for a children's publishing company and my significant other, David, is a mechanical engineer.

I would confirm with city inspection department that it is a legal 2 unit.

Dear BP,This site offers a LOT of useful info (and great calculators) helping newbies to start investing into residential real estate: rental SFRs, multiplexes, condos...

If your current investments are proving to be profitable you should have no problem.Check out some credit union's business/commercial loan department and see what they can do for you.

It's a health department thing.

On the other hand, I use Yelp and find out what people think of their building department and can get some insight on what I am walking into should repairs be in order.http://www.yelp.com/biz/village-of-brookfield-broo...Generally, if you take a couple hours online and do some research, you can avoid a lot of hidden issues.

I have an educator background and my husband has served in the military and now works for the sheriff department.

I would call a local credit union and talk to their business/commercial loans department.  

A very dear friend owns and lives in a 1960s middle class 3/2/2, around 1,600 s.f.

Armed with that information I called my credit union and spoke with the commercial department and was told id need 30 percent down plus other associated fees.