Most listings are in the $10's per square foot per year. The Hanahan submarket is experiencing a a boost in rates. In the last 3 months, the median rate rose $19 per sqft per year.
In the last 90 days, 4 listings have been listed, which means new availabilities most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About 75% of the office spaces in the Hanahan are subleases, so you might be able to sign a shorter term by taking over a previous 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 580 sqft. Most buildings in this area are around 3 floors. Most buildings in this region were built in 1980 and are Class B.