The typical asking rate per listing is in the $20's per square foot per year. The Wheaton region is going through a an increase in rates. In the last 3 months, the median rate went up $26 per sqft per year.
Compared to the rest of the Washington D.C. market, the Wheaton submarket has less expensive rates, so you should have no trouble finding a great deal in this discounted region.
In the last 90 days, 0 listings have been listed, which means office spaces are probably going fast. You'll want to be prepared to tour spaces as quick as possible. About Inf% of the listings in the Wheaton are subleases, so you might be able to snag a great spot on a short term. 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 2,500 sqft. Most properties in this area are approximately 1 floors. Most buildings in this market were built in 1986 and are Class B.