On average, listings lease in the $40's per square foot per year. The Castro Valley region is going through a a rise in rates. In the last 3 months, the median rate went up $44 per sqft per year.
Compared to the rest of the East Bay market, the Castro Valley submarket has greater rates, and you'll need to pay a premium to be in this hot submarket.
In the last 90 days, 0 listings have come on the market, which means spaces most likley are leasing quickly. You'll want to be prepared to tour spaces as quick as possible. About Inf% of the listings in the Castro Valley are subleases, so you might be able to find a shorter term or below market rent. 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 1,400 sqft. Most buildings in this region are approximately 1 floors. Most buildings in this region were built in 1982.