Most listings are in the $40's per square foot per year. The Belltown region is going through a a rise in rates. In the last 3 months, the median rate rose $1 per sqft per year. That's a 3% increase in rent.
Compared to the rest of the Seattle Metropolitan Area market, the Belltown submarket has more expensive rates, and you'll need to make a great offer to be in this hot region.
In the last 90 days, 35 listings have been listed, which means listings most likley are going fast. You'll want to be prepared to make an offer immediately. About 60% of the listings in the Belltown 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.
The standard measurement for office space in this area is around 2,020 sqft. Most properties in this region are approximately 5 floors. Most buildings in this market were built in 1967 and are Class A.
A large portion of this market is residential, but there's plenty of office_space. Arts, entertainment, and restaurants are the dominant industries in this market. Most of the folk of Belltown work from home. Commuting close to 10 minutes a day is the norm for those who opt to reside in this part of town.