In the last 90 days, 0 listings have been listed, which means leases most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About NaN% of the listings in the Kennett Square are subleases, so you will probably have to consider a longer term lease. 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 buildings in this market are around 3 stories.