On average, listings lease in the $20's per square foot per year. The Northwest Side region is experiencing a a rise in rates. In the last 3 months, the median rate went up $3 per sqft per year. That's a 13% rise in rent.
Compared to the rest of the Chicagoland market, the Northwest Side region has lower rates, so you should have no trouble finding a great deal in this depreciated submarket.
In the last 90 days, 65 listings have been made available, so you'll want to check back regularly for new listings. About 3% of the available leases in the Northwest Side are subleases, so you will probably have to focus your search on direct office leases. 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 2,290 sqft. Most buildings in this area are close to 2 stories. Most buildings in this market were built in 1950 and are Class A.