Most listings are in the $20's per square foot per year. The Delafield region is going through a an increase in rates. In the last 3 months, the median rate increased $21 per sqft per year. That's a Inf% rise in rent.
In the last 90 days, 2 listings have been made available, which means new listings most likley are leasing quickly. You'll want to be prepared to make an offer immediately. 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 1,660 sqft. Most buildings in this market are approximately 3 floors. Most buildings in this area were built in 1999 and are Class B.