On average, listings lease in the $30's per square foot per year. The Napa submarket is experiencing a an increase in rates. In the last 3 months, the median rate rose $4 per sqft per year. That's a 11% increase in rent.
In the last 90 days, 34 listings have been listed, which means new listings are probably 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 1,440 sqft. Most buildings in this region are approximately 1 stories. Most buildings in this area were built in 1983 and are Class A.