The Seattle Art Museum is one of the foremost cultural institutions in the Pacific Northwest. A significant increase in the museum’s holdings and a visionary public-private partnership were the catalysts for the construction of a new 16-story building. The 450,000sf expansion and renovation project allows SAM to grow incrementally, converting lease space to new exhibition galleries over a period of 20 years. The new building sits on First Avenue overlooking Elliott Bay. It is primarily a western prospect, with views extending to the Olympic Range. Four exterior “shells” form the boundary of the building and site, each responding to a particular orientation. Their surfaces of flush glass, fixed and operable stainless steel panels engage varied light – filtering, reflecting, and diffusing it into the exhibition spaces. At the street, the museum is open and transparent, providing glimpses into the galleries from the sidewalk below. Rising through the lobby, the exhibition spaces are defined by parallel structural walls that filter light and provide views deep into the center of the block. These walls create rooms of varied proportion and height, providing a broad spatial palette for the curators and the collection. The museum is ordered by an internal landscape of double-height galleries that intersect exhibition floors above, drawing the eye further up into the heart of the museum. The expansion is an open field for vertical growth, both lens and filter for a shifting series of relationships with art and landscape.