On average, listings lease in the $10's per square foot per year. The Southwest Side submarket is going through a an increase in rates. In the last 3 months, the median rate went up $19 per sqft per year. That's a Inf% increase in rent.
Compared to the rest of the Chicagoland market, the Southwest Side submarket has less expensive rates, so you should have no trouble finding a great deal in this depreciated region.
In the last 90 days, 9 listings have been listed, which means leases are probably going fast. You'll want to be prepared to tour spaces as quick as possible. About 11% of the available leases in the Southwest Side are subleases, so you might be able to snag a great spot on a short term. There aren't many listings below 2,000 square feet on the market, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,500 sqft. Most properties in this market are approximately 1 stories. Most buildings in this region were built in 1954 and are Class A.