On average, listings lease in the $30's per square foot per year. The Broadway region is going through a a rise in rates. In the last 3 months, the median rate increased $0 per sqft per year. That's a 1% rise in rent.
Compared to the rest of the Seattle Metropolitan Area market, the Broadway region has more expensive rates, and you'll have to negotiate above asking rent to be in this hot region.
In the last 90 days, 10 listings have been made available, which means listings are probably going fast. You'll want to be prepared to tour spaces as quick as possible. About 10% of the listings in the Broadway are subleases, so you will probably need to consider the implications of signing a direct lease with the building. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,300 sqft. Most properties in this market are around 3 stories. Most buildings in this area were built in 1917 and are Class B.
Not much of the real estate is used for commercial space, so it might be hard to find office space. Information is the dominant industry in this area. Most of the occupants of Broadway work from home. Commuting approximately 10 minutes a day is the norm for those who opt to reside in this part of town.