The typical asking rate per listing is in the $0's per square foot per year. The Lowell submarket is going through a decline in rates. In the last 3 months, the median rate fell $18 per sqft per year. That's a 100% decline in rent.
In the last 90 days, 5 listings have been posted online, which means listings most likley are leasing quickly. You'll want to be prepared to tour spaces as quick as possible. About 20% of the listings in the Lowell 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 posted, so finding a space for a small business might be tough.
Even though the median size is 5,650 sqft, there are still 0 office spaces below 2,000 sqft. Most buildings in this region are close to 4 floors. Most buildings in this area were built in 1977 and are Class B.