Most listings are in the $20's per square foot per year. The Windsor submarket is seeing a a boost in rates. In the last 3 months, the median rate went up $28 per sqft per year. That's a Inf% rise in rent.
Compared to the rest of the Bay Area market, the Windsor region has lower rates, so you should have no trouble finding a great deal in this discounted region.
In the last 90 days, 12 listings have been listed, which means spaces are probably going fast. 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 960 sqft. Most properties in this market are around 2 stories. Most buildings in this market were built in 2003 and are Class A.