Most listings are in the $40's per square foot per year. The The Loop submarket is going through a a boost in rates. In the last 3 months, the median rate went up $1 per sqft per year. That's a 3% increase in rent.
Compared to the rest of the Chicagoland market, the The Loop region has higher rates, and you'll need to pay a premium to be in this hot submarket.
In the last 90 days, 95 listings have been made available, so you'll want to check back regularly for new listings. About 15% of the available leases in the The Loop 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 available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 2,380 sqft. Most properties in this region are around 24 floors. Most buildings in this market were built in 1929 and are Class B.