Most listings are in the $10's per square foot per year. The Hanahan region is going through a an increase in rates. In the last 3 months, the median rate increased $19 per sqft per year.
In the last 90 days, 4 listings have been listed, which means spaces might be going fast. You'll want to be prepared to make an offer immediately. About 75% of the listings in the Hanahan 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 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 580 sqft. Most buildings in this region are approximately 3 floors. Most buildings in this market were built in 1980 and are Class B.