In the last 90 days, 4 listings have been made available, which means new availabilities most likley are going fast. You'll want to be prepared to make an offer immediately. About 25% of the available leases in the Fairmount Park are subleases, so you might be able to find a shorter term or below market rent. 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 1,050 sqft. Most properties in this region are around 29 stories. Most buildings in this region were built in 2005 and are Class A.