Renton Library Lot size: 46,400 SF Building size: 19,718 GSF Location: Renton, WA Project Type: Built
RENTON LIBRARY The original 1966 library structure was constructed to iconically straddle the Cedar River with views to the water, railway, and active salmon habitat. Its unique location was well loved by generations of community members and well worth preserving. When built in 1966, the original building was an engineering feat. Its pre-cast concrete T’s, concrete columns and wood truss-joists created an impressive 80’ central clear span on the interior. By 2015, however, the exterior envelope was failing and not compliant with current energy codes. Its structural system was not fit to withstand current seismic criteria nor potential liquefaction of the alluvial soils. In addition, its building systems were not able to keep up with the increased demands of a 21st century library—heavy in power and data usage. The team’s design goal was to celebrate and reveal the inherent bridge structure in a language recalling the Renton’s legacy of engineering. New cross bracing and raw aluminum siding was
detailed to celebrate a structurally expressive and finely crafted exterior expression. The renovation maintained the original super structure, but introduced a new energy efficient exterior envelope with floor to ceiling views to the river. By removing the interior attic space concealing the trusses, the interior volume increased by nearly 5’. Trimming back the existing overhang brought more daylight into the building and created a lightweight, taut bridge expression. Redistributing services throughout the concrete bridge structure proved to be problematic, so out of necessity, all of the building’s systems are revealed in the main public space as a way of putting the building’s “machine” on display. Digital information—essential to a 21st century library—was given celebrity status via power and data drops from the ceiling. These drops combine aircraft cable with steel connections and visually anchor the computer station “hubs” and study tables.
Inspiration for the renovation came from revealing the true nature of the library as bridge, expressed in a finely engineered raw aluminum and glass enclosure.
CONTEXT Renton, WA, located on the south shore of Lake Washington, has a long history of engineering and manufacturing including companies like PACCAR and Boeing. At the same time the library’s structure is one of a series of bridges—vehicular, rail and pedestrian—crossing the Cedar River within the downtown core.
BEFORE & AFTER The original library was unique for its location and unobstructed interior clear spans. However, its lack of transparency and impression of a thick roof plane created an expression that was at odds with its impressive overwater site. Today, the library’s raw aluminum panels, expressed structure and full height views bring the library’s mission to life and connect users to the river below.
SITE CONSTRAINTS The original 1966 structure, while iconic, could not have been built over the river with today’s environmental restrictions. This meant that all construction activity was required to remain outside of an area defined by the Ordinary High Water Mark and Base Flood Elevation. In order to seismically upgrade the building, the team creatively found a way to buttress the existing structure and soils using landward pilings—avoiding years of permitting oversight and habitat disruption. During construction, the contractor kept all construction activity and materials inside the bridge footprint, without the use of scaffolding or platforms that would disrupt the river’s hydraulic patterns.
+ 45.62’ Finish Floor + 39.62’ Base Flood Elevation (BFE) + 34’ Ordinary High Water Mark (OHWM)
NO CONSTRUCTION ZONE Due to the fragile river ecosystem, no new construction could occur below or waterward of the Base Floor Elevation (BFE).
ELEVATIONS
SOUTH ELEVATION
WEST ELEVATION
DECONSTRUCTION/CONSTRUCTION
1. EXISTING STRUCTURE
2. REMOVE 1980’s ADDITION & CLERESTORY
3. TRIM BACK ROOF STRUCTURE
4. ADD AUGER CAST PILES
5. ERECT BRACED FRAMES
6. INSERT NEW ENERGY EFFICIENT ENVELOPE & FULL HEIGHT GLAZING
7. INSTALL PERIMETER SUNSHADE
8. IMPROVE BRIDGE & RAILING
9. RENOVATED LIBRARY
SITE PLAN The library’s location straddling the river was an iconic one—and provided an important connection between the downtown and City Park. Public art located on both sides of the building—and within the building—enliven the city trail and bridge route for pedestrians. Views of the building from nearby bridges downriver and upriver now reflect a glowing destination of community activity.
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FLOOR PLAN
CEDAR RIVER
The floor plan was designed to celebrate the 80’ central clear span, and preserve views to the river. Enclosed spaces such as staff work areas, study rooms and building support were collected at each end of the “bridge”. The central clear span, with full height glazing, houses highly active program elements such as computers, browsing collections, childrens’ spaces and reading areas. The relocated entry is now accessible and visible from the parking lot. The new meeting room opens up to the library space, giving it valuable spill-out potential.
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PEDESTRIAN BRIDGE
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KEY:
1. Entry
2. Periodicals 3. Meeting Room 4. Teen Area 5. Study 6. Conference Room 7. Non-Fiction Collection 8. Computer Stations 9. Fiction 10. Children’s Area 11. Work Room
The existing pedestrian connection between the parking lot and City park is now accessible, well lit, and has a traction coating for safer crossing during wet/icy weather. The new railing is designed to feel transparent and allow better views to the river below. Lighting was incorporated into the railing for safety, yet is angled to prevent light spillage affecting salmon habitat.
INTERIOR EXPRESSION The interior of the building was renovated to honor the large open spans and industrial structure. Clean simple shapes and color palette were crafted to recall Renton’s manufacturing history, and colors used in those environments (safety orange and yellow).
interior finishes direction
KCLS RENTON DOWNTOWN LIBRARY
12.12.2013
Power/data distribution—vital for library functionality in 2015—was problematic to expand in a concrete precast structure. The team designed overhead power drops using aircraft able and steel connections to deliver power to study tables and computer stations. The unconcealed power and data cabling suggests a raw honesty for the information age library.