On average, listings lease in the $20's per square foot per year. The Portsmouth submarket is experiencing a an increase in rates. In the last 3 months, the median rate went up $5 per sqft per year. That's a 22% increase in rent.
Compared to the rest of the Greater Boston market, the Portsmouth submarket has greater rates, and you'll have to negotiate above asking rent to be in this hot submarket.
In the last 90 days, 23 listings have come on the market, which means office spaces are probably going fast. You'll want to be prepared to tour spaces as quick as possible. About 22% of the listings in the Portsmouth 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 2,450 sqft. Most properties in this area are close to 2 stories. Most buildings in this region were built in 1918 and are Class A.