how is multi different from SF

[Heather U.]

I have 5 SF properties but now am looking to buy a multi (might not be 5 units-hope this is still the right place to post.)  With the SF's I feel comfortable with my criteria I use to decide to buy or not and I feel I have a pretty good idea on what to expect as expenses etc... But last night I started looking at Multi and I suddenly felt overwhelmed!!

Please teach me what is different between the two so I can be prepared.  What expenses do I need to consider?  What criteria do you use when analysing a deal (is it pretty similar to a SF?) Is it still possible to get do a conventional loan at %20 down? 

ETc.... all ideas and thoughts welcome. Thank you!!!