Most listings are in the $30's per square foot per year. The Santa Clarita region is experiencing a an increase in rates. In the last 3 months, the median rate increased $4 per sqft per year. That's a 14% rise in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Santa Clarita region has smaller rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 47 listings have been made available, so you'll want to check back regularly for new listings. About 2% of the available leases in the Santa Clarita 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 posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,420 sqft. Most buildings in this region are close to 2 stories. Most buildings in this region were built in 2001 and are Class A.