On average, listings lease in the $30's per square foot per year. The Santa Clarita region is going through a a rise in rates. In the last 3 months, the median rate went up $36 per sqft per year.
Compared to the rest of the Metropolitan Los Angeles market, the Santa Clarita submarket has smaller rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 62 listings have been posted online, so you'll want to check back regularly for new listings. About 129% of the available leases in the Santa Clarita 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 2,000 sqft. Most properties in this market are close to 2 floors. Most buildings in this area were built in 2001 and are Class A.