In the last 90 days, 0 listings have been made available, which means new listings most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About NaN% of the available space in the Miami are subleases, so you will probably need to sign a longer term lease with the landlord directly. 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 region were built in 1915.