In the last 90 days, 2 listings have been made available, which means office spaces are probably leasing quickly. You'll want to be prepared to make an offer immediately. About 150% of the office spaces in the Somerville 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 sqft. Most properties in this region are close to 3 stories. Most buildings in this market were built in 1950 and are Class C.