Most listings are in the $10's per square foot per year. The Williamsburg submarket is experiencing a an increase in rates. In the last 3 months, the median rate rose $18 per sqft per year.
In the last 90 days, 5 listings have been posted online, which means office spaces are probably leasing quickly. You'll want to be prepared to make an offer immediately. About 100% of the listings in the Williamsburg 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 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 1,500 sqft. Most properties in this market are close to 2 stories. Most buildings in this market were built in 1980 and are Class B.