The typical asking rate per listing is in the $20's per square foot per year. The Vacaville region is experiencing a a boost in rates. In the last 3 months, the median rate went up $25 per sqft per year.
Compared to the rest of the Bay Area market, the Vacaville region has less expensive rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 1 listings have been made available, which means spaces are probably leasing quickly. You'll want to be prepared to make an offer immediately. 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 470 sqft. Most buildings in this area are around 1 stories. Most buildings in this market were built in 1988 and are Class A.