Most listings are in the $40's per square foot per year. The Darien region is seeing a a rise in rates. In the last 3 months, the median rate rose $20 per sqft per year. That's a 75% increase in rent.
Compared to the rest of the Fairfield market, the Darien region has higher rates, and you'll have to negotiate above asking rent to be in this hot region.
In the last 90 days, 5 listings have been listed, which means listings 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.
The standard measurement for office space in this area is around 2,200 sqft. Most buildings in this region are approximately 2 stories. Most buildings in this market were built in 1980 and are Class A.