On average, listings lease in the $10's per square foot per year. The Pleasant Hill region is going through a an increase in rates. In the last 3 months, the median rate rose $15 per sqft per year.
In the last 90 days, 7 listings have come on the market, which means office spaces are probably going fast. You'll want to be prepared to make an offer immediately. 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 2,480 sqft. Most buildings in this market are around 2 floors. Most buildings in this area were built in 1998 and are Class A.