On average, listings lease in the $20's per square foot per year. The Trumbull region is seeing a a rise in rates. In the last 3 months, the median rate rose $3 per sqft per year. That's a 13% rise in rent.
Compared to the rest of the Fairfield market, the Trumbull region has less expensive rates, so you should have no trouble finding a great deal in this depreciated region.
In the last 90 days, 14 listings have been posted online, which means listings most likley are leasing quickly. You'll want to be prepared to make an offer immediately. There aren't many listings below 2,000 square feet on the market, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,950 sqft. Most properties in this area are approximately 3 stories. Most buildings in this area were built in 1986 and are Class B.