On average, listings lease in the $30's per square foot per year. The Chino region is going through a a rise in rates. In the last 3 months, the median rate rose $14 per sqft per year. That's a 72% increase in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Chino region has less expensive rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 10 listings have come on the market, which means spaces are probably going fast. You'll want to be prepared to tour spaces as quick as possible. About 30% of the office spaces in the Chino are subleases, so you might be able to sign a shorter term by taking over a previous lease. 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 2,270 sqft. Most properties in this region are around 1 stories. Most buildings in this region were built in 2003 and are Class A.