Most listings are in the $40's per square foot per year. The Napa submarket is seeing a decrease in rates. In the last 3 months, the median rate fell $4 per sqft per year. That's a 8% decrease in rent.
Compared to the rest of the Bay Area market, the Napa region has greater rates, and you'll need to make a great offer to be in this hot region.
In the last 90 days, 23 listings have come on the market, which means listings are probably leasing quickly. You'll want to be prepared to tour spaces as quick as possible. About 30% of the available space in the Napa are subleases, so you might be able to find a shorter term or below market rent. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
Even though the median size is 2,990 sqft, there are still 0 new availabilities below 2,000 sqft. Most properties in this area are close to 2 floors. Most buildings in this area were built in 1980 and are Class B.