Most listings are in the $20's per square foot per year. The Charleston region is going through a an increase in rates. In the last 3 months, the median rate rose $1 per sqft per year. That's a 5% increase in rent.
In the last 90 days, 1 listings have been listed, which means office spaces are probably leasing quickly. You'll want to be prepared to tour spaces as quick as possible. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
Even though the median size is 68,670 sqft, there are still 0 spaces below 2,000 sqft. Most buildings in this area are close to 12 stories. Most buildings in this region were built in 1984 and are Class B.