Seattle Public Library designed by the firms OMA (Office for Metropolitan Architecture) and LMN Architects, constructed by Hoffman Construction Company and completed in 2004. The reason why I choose this structure is its unique approaches regarding creating a floating space with minimum supports but without losing the purpose of providing functionality. Creating such a respectable structure is only achieved by a strong client and an innovative architect. The client is Deborah L. Jacobs, who is Seattle’s city librarian. She asks for a continuing space with surrounded by books, and a centralized area at the center. Then the architect, Rem Koolhaas and his partners have perfectly achieved a design composed of lots of public spaces as a compact manner.
This report presents the general layout of exterior and interior design of the building, their close relationship with the structural systems and some diagrams.
Seattle public library is very irregular and unusual from the outside. It is a massive glass building with straight lines that intersect. And in the interior, the design shaped by the abstract volumes.
The design of the building is so compact and continuous that it provides not only visual connectivity and visual integration but also functionality. The concept of the building is to provide easily accessible spaces with different characteristics. Koolhaas designed the whole project that the building can be flexible for future expansions with the possibility of grouping of spaces according to the needs of the building and the platforms connected to the study would provide open spaces, work and social interaction.
Even though the structure has eleven floors, it has some kind of continuity around the floors. Since the main concern of the design of the building is having a functionality of a library; instead of placing books on different shelves and floors, the spiral inclined allowed a continuous row of book.
This spiral that rises for 4 floors, has created a zigzag ramp throughout the building. These ramps are supported on slender columns constructed economically.
The interior volume is divided into 5 distinguishable blocks from the outside. These blocks are generates stable and unstable platforms at the inside. Each platform has different structural system and volume.
The layout of the interior design has separated into different functionalities yet still considered as a whole. There formed five stable and four unstable platforms.
Stable platforms (red) are dedicated for specific purposes such as parking garage, storing area for the usage of staff members, meeting rooms, a large spiral of books and administrative offices. Unstable platforms (white) are located in between the stable platforms and dedicated especially for activities, such as living room, reading room, kids’ playing room etc. The multi-floor escalators originate in unstable platforms only, although passing the stable platforms.
Since the main focus of this public space is reading, the building illuminated with sun light coming through the glass walls. But the glass walls provide not only natural lights but also a part of its structural system. Whole building covered with a skin of glass and steel, yet the designers wanted to use no columns on the corners and fewest numbers of columns at total. It would not be easy to carry the loads of such structure so they had to find an optimum way of using columns.
The design process of Seattle Public Library has been reviewed from many aspects not only for aesthetics but also structural capacity, thermal performance, maintenance and constructability.
In general, the structural system of the building composed of both load-bearing and seismic system.
Load-bearing system which are columns and beams, support the gravity loads of elevated platforms and cantilevers. And seismic structure in the form of the steel grid of diamond-shaped system provides stability during a seismic event.
In order to minimize the number of columns and beams, many of them were given angle to connect each other so that they can transfer loads to the central core or other columns.
Core columnar members carry the gravity load of the building.
On the other hand, the steel grid system opposes the lateral system of the building and supports the glass covering.
The diagonal grid system is designed to withstand lateral forces caused by wind or earthquakes.
The grid works as a huge frame, collecting seismic forces from each platform and transferring to the groundIt has a diamond shape and was determined by considering the optimum size for fabrication, construction and aesthetic.
Here is a diagram of loaf distribution of wind loads and gravitational loads of the building and their way of transition to the ground.
Melis Kucuktunc 