The answer came from the SAM web site, where I found out what a lot of you may already know: This building is a partnership between Washington Mutual Bank and the Seattle Art Museum.

Planning for the expansion of both entities, the new building will allow SAM to more than double its current size when the new building opens and triple floor space in later years reaching a total of 450,000 square feet, making SAM one of the largest art museums in the country.

Washington Mutual will occupy the Second Avenue side and the majority of the upper floors where they’ll consolidate staff, currently spread over 12 buildings throughout the city.

The new art space should open in the summer of 2007. The first two floors will be public space, no admission necessary. The expansion will triple the restaurant size, double the museum store and add a new entrance on First and Union that will draw people in with "natural light and views of Elliott Bay and the city." Also, 710 parking spaces are planned with many of those available for museum parking as well as evening parking near Benaroya Hall and Pike Place Market.

You can keep tabs on this new building with the museums "Sam Cam" perched high atop the current Washington Mutual tower.