On average, listings lease in the $10's per square foot per year. The Rohnert Park submarket is seeing a decline in rates. In the last 3 months, the median rate fell $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 smaller rates, so you should have no trouble finding a great deal in this undervalued submarket.
In the last 90 days, 13 listings have been posted online, which means leases 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 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 600 sqft. Most properties in this region are around 2 stories. Most buildings in this area were built in 1986 and are Class B.