On average, listings lease in the $10's per square foot per year. The Porterville submarket is experiencing a a boost in rates. In the last 3 months, the median rate increased $16 per sqft per year.
In the last 90 days, 2 listings have been made available, which means office spaces most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About 50% of the available leases in the Porterville are subleases, so you might be able to snag a great spot on a short term. 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 1,000 sqft. Most buildings in this area are approximately 1 floors. Most buildings in this area were built in 2001 and are Class B.