In the last 90 days, 4 listings have been posted online, which means spaces most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About 25% of the office spaces in the Glen Cove 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.
The standard measurement for office space in this area is around sqft. Most properties in this region are approximately 3 floors. Most buildings in this market were built in 1989 and are Class A.