Most listings are in the $20's per square foot per year. The Walnut region is seeing a a rise in rates. In the last 3 months, the median rate rose $23 per sqft per year. That's a Inf% rise in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Walnut region has lower rates, so you should have no trouble finding a great deal in this undervalued submarket.
In the last 90 days, 1 listings have been made available, which means listings might be going fast. You'll want to be prepared to tour spaces as quick as possible. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 960 sqft. Most buildings in this area were built in 1987.