A significant design challenge of the Walnut Creek Library was to replace an outdated 10,000 SF building with a new one four times its size without encroaching further into its urban park site. The library has a public entrance on each side in response to its unique site, which is adjacent to the park to the north, the citys civic center to the west, the downtown commercial district to the south, and residential neighborhoods to the east. The new library welcomes visitors from all directions, drawing them into the building through the use of a strong north-south axis. The librarys gently curving facades draw the parks open spaces around the building and create a new plaza on the south side. An expanded plaza on the park north side is the setting for civic and community events.
The curving forms of the exterior facades became a signature design element repeated in dramatic arcing roof forms and a striking serpentine wood ceiling. The building opens up to park views to the north through large expanses of glass, while clerestory windows throughout the building bring daylight deep into the interior. Warm materials such as brick and wood enhance the buildings connection to the park. Whimsical windows on the west facade create cozy reading nooks in the Childrens Library and offer passersby a glimpse of the activities within.
Automated materials handling, customer self-service opportunities, and excellent visibility for supervision contribute to a highly efficient 42,000 square foot library that operates with just 14 FTE. The design supports multiple operational modes, providing the ability to operate portions independently for extended hours with reduced staffing including the second floor “Conference Center” with program room, conference room, and technology lab; and the “Marketplace” with new and popular materials, public computers, customer holds, a cafe, and a bookstore. The Conference Center is also a source of revenue with frequent community rentals.
Public art is featured prominently, with major works including a 26 high shelf of books with spines in varying shades of gray that can be changed to reveal different images over time; and a sculpture celebrating ecological responsibility suspended over the north stair. Community artwork is also celebrated through display in the Marketplace.
Sustainable design was a significant consideration. The new library achieved LEED Gold certification through a variety of strategies, from strong urban connections to a high level of energy efficiency and the use of recycled content materials:
– Site. The new library is close to commuter rail and is on multiple bus routes. Maximizing open space and reducing the heat island effect was achieved by locating 80 of the parking spaces in an underground garage.
– Solar. With a long north-south orientation of the site, the building is exposed to the strong morning and afternoon sun. External shading devices and motorized interior shades mitigate excessive direct sunlight into the library.
– Energy. The library is equipped with energy efficient heating, cooling, and lighting systems; under-floor HVAC distribution; and daylight harvesting controls to dim building zones when they receive sufficient daylight. The building is photovoltaic-ready.
– Envelope. The highly insulated building envelope is constructed of durable materials that celebrate the librarys park setting, including low- emissivity glass curtain walls, plaster walls, brick panels, Ipe wood panels, and metal trim.
– Lighting. Large windows and curtain walls provide daylighting and views out from 95 of regularly-occupied spaces. Photocells, occupancy sensors, and automatic continuous dimming controls maximize lighting energy savings. Floor plates are shallow to maximize daylight penetration into the space. Large user-level and clerestory windows provide even, natural daylight to the interior spaces.
– Water. Stormwater from the roof is directed into flow-through planters that filter the water before it enters the stormwater system. Site stormwater is directed into bioswales where it is filtered through layers of rock. Inside the building, ultra low-flow urinals, water efficient fixtures, and sensor faucets are used to reduce potable water consumption by at least 35.