Compared to the rest of the Seattle Metropolitan Area market, the Mercer Island region has higher rates, and you'll need to make a great offer to be in this hot region.
In the last 90 days, 1 listings have been listed, which means new availabilities most likley are going fast. You'll want to be prepared to make an offer immediately. 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 980 sqft. Most properties in this market are around 2 stories. Most buildings in this region were built in 1982 and are Class B.