On average, listings lease in the $20's per square foot per year. The Hayward region is seeing a a rise in rates. In the last 3 months, the median rate increased $29 per sqft per year.
Compared to the rest of the East Bay market, the Hayward region has smaller rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 15 listings have been made available, which means leases are probably going fast. You'll want to be prepared to make an offer immediately. About 33% of the listings in the Hayward 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 1,300 sqft. Most properties in this area are around 1 floors. Most buildings in this area were built in 1977 and are Class A.