The typical asking rate per listing is in the $30's per square foot per year. The Central Houston region is going through a an increase in rates. In the last 3 months, the median rate rose $4 per sqft per year. That's a 16% rise in rent.
Compared to the rest of the Houston Metro market, the Central Houston region has higher rates, and you'll need to make a great offer to be in this hot region.
In the last 90 days, 260 listings have been made available, so you'll want to check back regularly for new listings. About 5% of the office spaces in the Central Houston are subleases, so you will probably need to consider the implications of signing a direct lease with the building. 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 1,250 sqft. Most properties in this region are close to 6 floors. Most buildings in this area were built in 1975 and are Class B.