Most listings are in the $30's per square foot per year. The Heathrow region is experiencing a a rise in rates. In the last 3 months, the median rate increased $6 per sqft per year. That's a 22% rise in rent.
In the last 90 days, 3 listings have come on the market, which means new listings most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About 300% of the available leases in the Heathrow are subleases, so you might be able to snag a great spot on a short term. There aren't many listings below 2,000 square feet on the market, so finding a space for a small business might be tough.
Even though the median size is 3,180 sqft, there are still 0 new availabilities below 2,000 sqft. Most properties in this market are around 3 floors. Most buildings in this region were built in 1996 and are Class A.