Most listings are in the $30's per square foot per year. The Fairfax submarket is seeing a decline in rates. In the last 3 months, the median rate decreased $1 per sqft per year. That's a 2% decrease in rent.
Compared to the rest of the Washington D.C. market, the Fairfax region has less expensive rates, so you should have no trouble finding a great deal in this discounted region.
In the last 90 days, 29 listings have come on the market, which means listings are probably 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 available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,930 sqft. Most buildings in this region are approximately 5 stories. Most buildings in this region were built in 1985 and are Class B.