The typical asking rate per listing is in the $10's per square foot per year. The Brillion region is going through a a boost in rates. In the last 3 months, the median rate went up $16 per sqft per year. That's a Inf% increase in rent.
In the last 90 days, 3 listings have come on the market, which means listings most likley are leasing quickly. You'll want to be prepared to tour spaces as quick as possible. 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 2,110 sqft. Most buildings in this region were built in 2007 and are Class B.