The typical asking rate per listing is in the $20's per square foot per year. The Andover region is going through a an increase in rates. In the last 3 months, the median rate went up $3 per sqft per year. That's a 19% increase in rent.
In the last 90 days, 13 listings have been made available, which means listings are probably going fast. You'll want to be prepared to make an offer immediately. About 85% of the available space in the Andover are subleases, so you might be able to find a shorter term or below market rent. 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 630 sqft. Most buildings in this market are approximately 1 floors. Most buildings in this area were built in 1997 and are Class A.