Most listings are in the $20's per square foot per year. The Castle Hills submarket is experiencing a a boost in rates. In the last 3 months, the median rate rose $3 per sqft per year. That's a 10% rise in rent.
Compared to the rest of the Greater Austin market, the Castle Hills region has greater rates, and you'll need to pay a premium to be in this hot region.
In the last 90 days, 19 listings have been made available, which means new listings most likley are going fast. You'll want to be prepared to make an offer immediately. 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 240 sqft. Most properties in this region are around 4 floors. Most buildings in this region were built in 1982 and are Class B.