On average, listings lease in the $0's per square foot per year. The Riverdale submarket is experiencing a decline in rates. In the last 3 months, the median rate fell $26 per sqft per year. That's a 100% decline in rent.
In the last 90 days, 0 listings have been posted online, which means office spaces most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About NaN% of the available space in the Riverdale are subleases, so you will probably have to consider a longer term lease. There aren't many listings below 2,000 square feet posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around sqft. Most buildings in this area are around 4 stories. Most buildings in this market were built in 2006 and are Class B.