On average, listings lease in the $30's per square foot per year. The Fairfax County submarket is going through a decline in rates. In the last 3 months, the median rate fell $3 per sqft per year. That's a 9% decline in rent.
In the last 90 days, 511 listings have come on the market, so you'll want to check back regularly for new listings. About 3% of the listings in the Fairfax County 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.
Even though the median size is 4,700 sqft, there are still 0 leases below 2,000 sqft. Most buildings in this market are around 4 floors. Most buildings in this region were built in 1987 and are Class A.