The typical asking rate per listing is in the $20's per square foot per year. The Whittier region is going through a decline in rates. In the last 3 months, the median rate fell $1 per sqft per year. That's a 3% decrease in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Whittier region has less expensive rates, so you should have no trouble finding a great deal in this depreciated submarket.
In the last 90 days, 20 listings have been posted online, which means listings are probably going fast. You'll want to be prepared to make an offer immediately. About 10% of the available space in the Whittier are subleases, so you will probably need to sign a longer term lease with the landlord directly. 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 1,200 sqft. Most buildings in this region are close to 2 floors. Most buildings in this area were built in 1974 and are Class B.