In the last 90 days, 1 listings have been listed, which means leases are probably going fast. You'll want to be prepared to tour spaces as quick as possible. About 100% of the office spaces in the Cos Cob are subleases, so you might be able to snag a great spot on a short term. 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 sqft. Most properties in this market are approximately 3 floors. Most buildings in this area were built in 1967 and are Class A.