On average, listings lease in the $20's per square foot per year. The Warrenton region is experiencing a an increase in rates. In the last 3 months, the median rate increased $1 per sqft per year. That's a 5% rise in rent.
Compared to the rest of the Washington D.C. market, the Warrenton region has lower rates, so you should have no trouble finding a great deal in this depreciated region.
In the last 90 days, 3 listings have been posted online, which means new availabilities might be leasing quickly. You'll want to be prepared to tour spaces as quick as possible. About 667% of the available space in the Warrenton are subleases, so you might be able to find a shorter term or below market rent. 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 1,110 sqft. Most properties in this market are around 3 floors. Most buildings in this area were built in 1991 and are Class A.