In the last 90 days, 1 listings have been made available, which means new listings most likley are going fast. You'll want to be prepared to make an offer immediately. About 100% of the listings in the Riverside 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 available, so finding a space for a small business might be tough.
Even though the median size is 3,180 sqft, there are still 0 new listings below 2,000 sqft. Most properties in this region are approximately 2 stories. Most buildings in this area were built in 1986 and are Class B.