On average, listings lease in the $30's per square foot per year. The Gaithersburg submarket is going through a a rise in rates. In the last 3 months, the median rate rose $32 per sqft per year.
Compared to the rest of the Washington D.C. market, the Gaithersburg region has greater rates, and you'll need to pay a premium to be in this hot region.
In the last 90 days, 20 listings have been listed, which means new listings most likley are leasing quickly. You'll want to be prepared to tour spaces as quick as possible. About 155% of the listings in the Gaithersburg 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 available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 2,200 sqft. Most properties in this market are approximately 2 stories. Most buildings in this area were built in 1989 and are Class B.