The typical asking rate per listing is in the $20's per square foot per year. The New Hampshire region is experiencing a a rise in rates. In the last 3 months, the median rate increased $1 per sqft per year. That's a 6% increase in rent.
In the last 90 days, 527 listings have been made available, so you'll want to check back regularly for new listings. About 2% of the listings in the New Hampshire are subleases, so you will probably need to consider the implications of signing a direct lease with the building. 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 2,400 sqft. Most buildings in this region are close to 2 stories. Most buildings in this area were built in 1928 and are Class Class B.