The typical asking rate per listing is in the $20's per square foot per year. The Northbrook submarket is seeing a an increase in rates. In the last 3 months, the median rate rose $5 per sqft per year. That's a 23% increase in rent.
Compared to the rest of the Chicagoland market, the Northbrook submarket has greater rates, and you'll have to negotiate above asking rent to be in this hot submarket.
In the last 90 days, 23 listings have come on the market, which means new listings are probably leasing quickly. You'll want to be prepared to make an offer immediately. About 4% of the available leases in the Northbrook are subleases, so you will probably need to sign a longer term lease with the landlord directly. There aren't many listings below 2,000 square feet posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,650 sqft. Most buildings in this area are close to 4 stories. Most buildings in this region were built in 1980 and are Class A.