On average, listings lease in the $30's per square foot per year. The Novato region is going through a an increase in rates. In the last 3 months, the median rate went up $16 per sqft per year. That's a 67% increase in rent.
Compared to the rest of the Bay Area market, the Novato submarket has smaller rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 55 listings have been listed, so you'll want to check back regularly for new listings. About 2% of the available space in the Novato are subleases, so you will probably need to sign a longer term lease with the landlord directly. There aren't many listings below 2,000 square feet posted, so finding a space for a small business might be tough.
Even though the median size is 2,880 sqft, there are still 0 new availabilities below 2,000 sqft. Most properties in this area are approximately 2 stories. Most buildings in this area were built in 1987 and are Class A.