On average, listings lease in the $10's per square foot per year. The Irmo region is going through a decline in rates. In the last 3 months, the median rate fell $4 per sqft per year. That's a 20% decrease in rent.
In the last 90 days, 3 listings have been listed, which means new listings most likley are 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 3,500 sqft, there are still 0 new listings below 2,000 sqft. Most buildings in this region were built in 2007 and are Class B.