The typical asking rate per listing is in the $10's per square foot per year. The Rohnert Park region is experiencing a decline in rates. In the last 3 months, the median rate decreased $2 per sqft per year. That's a 13% decrease in rent.
Compared to the rest of the Bay Area market, the Rohnert Park region has lower rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 13 listings have been listed, which means new availabilities 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.
The standard measurement for office space in this area is around 600 sqft. Most buildings in this market are around 2 floors. Most buildings in this region were built in 1986 and are Class B.