Multi family in Chicago area

[Jeff Morrison]

We are looking to get started in small multifamily buildings, ie duplex, triplex, quad. We live in the NW suburbs of Chicago and it seems like the most affordable ones are in the Elgin area, Aurora or in the city. Elgin would be the closest to where I live. All 3 areas they usually are 100+ year old properties. Other than the obvious of older plumbing, electrical, what else should I look out for? Are these buildings still worth the investment? We also own a condo and a single family house that are both rented out.