Most listings are in the $20's per square foot per year. The Franklin submarket is going through a an increase in rates. In the last 3 months, the median rate went up $24 per sqft per year.
Compared to the rest of the Greater Boston market, the Franklin region has greater rates, and you'll have to negotiate above asking rent to be in this hot region.
In the last 90 days, 6 listings have been made available, which means office 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 on the market, so finding a space for a small business might be tough.
Even though the median size is 7,200 sqft, there are still 0 new availabilities below 2,000 sqft. Most properties in this region are around 2 stories. Most buildings in this area were built in 1930 and are Class B.