The typical asking rate per listing is in the $30's per square foot per year. The Fairfax submarket is going through a a rise in rates. In the last 3 months, the median rate went up $1 per sqft per year. That's a 3% rise in rent.
Compared to the rest of the Washington D.C. market, the Fairfax submarket has lower rates, so you should have no trouble finding a great deal in this depreciated submarket.
In the last 90 days, 16 listings have been made available, which means leases might be leasing quickly. You'll want to be prepared to tour spaces as quick as possible. 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 1,300 sqft. Most buildings in this area are approximately 5 floors. Most buildings in this market were built in 1985 and are Class B.