Salk Institute Conservation Project

Completed in 1965, the Salk Institute for Biological Studies in La Jolla, California is considered one of architect Louis I. Kahn's finest works and an iconic work of modern architecture with international significance. In 2013, we partnered with the Salk Institute to address the aging and long-term care of the building's teak window wall assemblies, which are one of the major elements of the architectural ensemble.


Kahn was commissioned by Jonas Salk, developer of the polio vaccine, to design an inspiring campus for his new scientific research institute, to be located on a coastal bluff overlooking the Pacific Ocean. Kahn's design consists of two nearly identical wings of laboratory, study, and office space mirroring each other on either side of a paved central plaza. The exterior materials palette consists of concrete, teak, glass, travertine, lead, and steel.

Set within the concrete walls of the study towers and office wings are 203 teak window wall assemblies, which consist of different combinations of horizontal sliding window, louver, and shutter sashes that allow staff to control light and air in their workspaces. The assemblies were constructed using teak structural members and softwood framing, with the exterior faces clad in vertical teak siding and the interior faces clad in oak paneling and gypsum board.

Although the assemblies were prefabricated, each one has a handcrafted quality due to the carpenters' detailing and customization of the units to fit into the many different sized wall openings. The window walls are significant elements of the site, expressing a human element and scale within the monumental structure. They are also significant within Kahn's larger body of work, as they expand upon a language of custom exterior millwork designed and established in his office.

After nearly fifty years in an exposed marine environment, the window walls had weathered to a non-uniform appearance and suffered from surface erosion; the growth of a fungal biofilm, likely spread by nearby eucalyptus trees, that gave the wood a black appearance that varied significantly by exposure; changes to the teak color due to previously applied sealers and finishes; insect infestation; and air and moisture infiltration. Given these conditions, the Salk Institute had originally assumed that total replacement might be necessary, but also recognized that such a project would result in the loss of a significant amount of the building's original material fabric.

Project Overview

In 2013, we began a collaborative partnership with the Salk Institute to determine if there was a way to conserve, rather than replace, the existing teak window wall assemblies and better protect the site's significance. The project, which utilized a standard conservation methodology, was divided into four phases.

Phase 1 (2013–14) included preliminary historical research and assessment of significance, condition surveys, investigative inspection openings, wood and fungus identification, analyses of past surface treatments, and diagnoses of weathering and deterioration mechanisms. Conservation principles and guidelines were prepared to guide the development of initial treatment approaches.

In phase 2 (2014–15), the GCI and the Salk's conservation architect, Wiss, Janney Elstner Associates, Inc. (WJE), carried out an in situ trial mock-up program to assess the initial treatment approaches, with interventions ranging from minor to moderate and major. All treatments addressed the fungal biofilm and included sensitive modifications to improve the overall performance of the assemblies.

During phase 3 (2015), WJE refined the treatment options and developed construction repair drawings and technical specifications.

The construction project, phase 4, began in 2016 and was completed in June 2017. One of the major successes of the project is that over two-thirds of the original Southeast Asian teak was conserved in place, preserving both a cultural and rare natural resource.

Project Objectives

Preserve the significance of the teak window wall assemblies, one of the principle building features contributing to the overall significance of the site, while maintaining their functionality and improving performance.

Demonstrate how a standard conservation-based methodology, rooted in scientific research, could be applied to address the window wall assemblies in a comprehensive long-term manner, as well as to the site's other significant historic elements, such as the concrete and travertine paving, in the future.

Assist the Salk Institute in making the shift from a maintenance-based to a conservation-based approach to caring for the site, which can be a challenging transition for many modern sites as they gain recognition as cultural heritage sites. As part of this, assist the institute in embedding this conservation approach in their asset management processes.

This project complements work supported by grants the Salk Institute received from the Getty Foundation's Keeping it Modern initiative for the development of comprehensive conservation management plan for the site and a concrete research and repair project.

Page updated: January 2019