On average, listings lease in the $20's per square foot per year. The Greenbelt region is seeing a a rise in rates. In the last 3 months, the median rate rose $7 per sqft per year. That's a 37% increase in rent.
Compared to the rest of the Washington D.C. market, the Greenbelt submarket has lower rates, so you should have no trouble finding a great deal in this undervalued submarket.
In the last 90 days, 30 listings have come on the market, which means office spaces are probably leasing quickly. You'll want to be prepared to make an offer immediately. 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 2,133 sqft. Most properties in this region are close to 8 stories. Most buildings in this region were built in 1984 and are Class A.