On average, listings lease in the $20's per square foot per year. The Bristol region is seeing a a rise in rates. In the last 3 months, the median rate increased $22 per sqft per year.
In the last 90 days, 4 listings have come on the market, which means listings most likley are leasing quickly. 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 2,100 sqft. Most buildings in this area were built in 1850 and are Class A.