On average, listings lease in the $50's per square foot per year. The Lowell submarket is going through a a boost in rates. In the last 3 months, the median rate rose $51 per sqft per year.
Compared to the rest of the Greater Boston market, the Lowell region has higher rates, and you'll have to negotiate above asking rent to be in this hot submarket.
In the last 90 days, 6 listings have come on the market, which means new availabilities are probably leasing quickly. You'll want to be prepared to tour spaces as quick as possible. 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 340 sqft. Most properties in this market are close to 4 floors. Most buildings in this region were built in 1977 and are Class B.