The typical asking rate per listing is in the $20's per square foot per year. The Portsmouth region is experiencing a a boost in rates. In the last 3 months, the median rate increased $5 per sqft per year. That's a 31% rise in rent.
In the last 90 days, 26 listings have been made available, which means spaces most likley are going fast. You'll want to be prepared to tour spaces as quick as possible. 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 2,310 sqft. Most buildings in this region are approximately 2 floors. Most buildings in this area were built in 1978 and are Class C.