Compared to the rest of the Chicagoland market, the Darien region has smaller rates, so you should have no trouble finding a great deal in this depreciated region.
In the last 90 days, 5 listings have been posted online, which means spaces are probably going fast. You'll want to be prepared to make an offer immediately. About 120% of the available space in the Darien 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 500 sqft. Most buildings in this area are approximately 1 stories. Most buildings in this region were built in 1990 and are Class B.