Location San Francisco
Size 4,800 ft²
Completed 2008
Program 9 classrooms, 2 art studios, 3 science labs, library

450 architects principals David Bushnell and Richard Parker are known for engaging multiple stakeholders in a project’s design, asking what a building and its environs can and should accomplish. They’re also advocates of both education and sustainability, so when the San Francisco Waldorf High School—an education system that values nature as a tool for learning— needed a new campus, the pair was a natural fit. What might not have seemed natural, however, was the brutalist, poured-in-place concrete structure originally built in the early 1970s that the architects had to work with. Here, the architects take us inside the renovation, a project that earned LEED Gold certification in 2011.


Architect 450 Architects
Client San Francisco Waldorf High School
General Contractor Oliver & Company

Concrete Casing

The philosophy of the Waldorf schools, which use a humanistic, sensory, and interdisciplinary approach to education, includes experiences in the outdoors. “Reverence for the Earth is ingrained in their philosophy,” Bushnell says. “We were able to transform a concrete shell that, to our surprise, was not only structurally sound after 40 years but met current seismic code requirements.” Part of the transformation involved the windows: dingy, single-pane, fixed-glazing windows were replaced with high-efficiency operable wood ones, increasing daylighting and providing natural ventilation (No.1).

Natural Interior

450 architects celebrated the structure’s original materials. “Exposed concrete respects the building for what it is,” Bushnell says. “It’s durable and was well-made. Rather than cover it, we juxtaposed a warm palette of natural materials and finishes.” Light fixtures positioned near windows are set to dim with daylight while those closer to the building core provide higher-intensity light.

The hard angles of the high school’s concrete structure are softened by its curved interior walls. The LEED Gold school teaches students core subjects through nature and art.

Class Specific

Though many high schools use a singularly designed science lab for biology, chemistry, and physics, Waldorf schools configure them differently for each subject. Here, the biology lab benches are separate from the lecture area, under all of which are concrete floors (No.2). Why concrete? “When future resources allow they will get rubber and cork floor coverings,” Bushnell says. “Concrete can suffice for now, instead of installing cheap vinyl or carpet.” Via the operable windows, a eucalyptus grove provides a therapeutic scent inside the building (No.3). Given San Francisco’s moderate climate, no mechanical air-conditioning is necessary with such a tight building envelope, and a boiler that is 99 percent efficient minimizes energy use.


Certification LEED Gold
Ventilation Natural cooling and air exchange via operable windows
Materials Cork flooring, wallboard with 98% recycled paper and 96% recycled gypsum
Air 99% efficient boiler, tight building envelope, no mechanical air-conditioning

Gallery Space

To contrast the hardness of the concrete, curved wall surfaces form a central hallway to soften the learning environment (No.4). “We had a raw, 80-foot by 60-foot space to work with,” Bushnell says. “We wanted to allow the space to naturally flow, to create places to congregate. This provided surfaces that were conceived to provide a gallery-like atmosphere for displaying art.” Bushnell says the project’s general contractor, Oliver & Company, was very adaptive to what the school was trying to do. Notable materials include the wallboard, which is made from 98 percent recycled paper and 96 percent recycled gypsum.

Artistic License

In its previous incarnation as an AT&T call center, what is now the textile arts classroom housed a backup generator to accommodate emergency functions in the case of an earthquake (No.5). Because Waldorf schools integrate the art of making things to also teach mathematics, physics, and astronomy, improving this space was vital. The architects cut windows into the concrete walls and transformed the vault into a light-filled studio, connecting the space to the outdoors.