In the last 90 days, 1 listings have been posted online, which means new listings most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About 300% of the office spaces in the North Miami Beach 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 sqft. Most properties in this area are around 2 stories. Most buildings in this area were built in 1972 and are Class B.