The typical asking rate per listing is in the $30's per square foot per year. The Novato region is going through a a rise in rates. In the last 3 months, the median rate rose $12 per sqft per year. That's a 50% increase in rent.
Compared to the rest of the Bay Area market, the Novato submarket has lower rates, so you should have no trouble finding a great deal in this depreciated region.
In the last 90 days, 49 listings have been posted online, so you'll want to check back regularly for new listings. About 2% of the office spaces in the Novato are subleases, so you will probably need to consider the implications of signing a direct lease with the building. 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 2,560 sqft, there are still 0 new listings below 2,000 sqft. Most properties in this area are around 2 stories. Most buildings in this area were built in 1987 and are Class A.