On average, listings lease in the $10's per square foot per year. The Glen Ellyn submarket is experiencing a a rise in rates. In the last 3 months, the median rate went up $18 per sqft per year.
Compared to the rest of the Chicagoland market, the Glen Ellyn region has less expensive rates, so you should have no trouble finding a great deal in this discounted submarket.
In the last 90 days, 5 listings have been made available, which means leases might be leasing quickly. You'll want to be prepared to make an offer immediately. About 20% of the available leases in the Glen Ellyn are subleases, so you might be able to sign a shorter term by taking over a previous lease. 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 1,000 sqft. Most buildings in this market are approximately 1 stories. Most buildings in this area were built in 1983 and are Class A.