A diagrammatic section of the library during daylight hours represents the different layers of light via color: white represents daylight, yellow signals light provided from tasklights, and blue codes the ambient light provided by fluorescent sources (above). A sectional study of the southern louver wall's egg-crate design (top right) and the corresponding shading mask overlay on the solar calculator (top left).
A diagrammatic section of the library during daylight hours represents the different layers of light via color: white represents daylight, yellow signals light provided from tasklights, and blue codes the ambient light provided by fluorescent sources (above). A sectional study of the southern louver wall's egg-crate design (top right) and the corresponding shading mask overlay on the solar calculator (top left).
 

This team collaboration, for the design of a scholar's library, locates the envisioned project on an actual site in New York City—13th Street and Fifth Avenue. There are three daylighting strategies utilized in the project: louvered walls, skylights, and floor setbacks. Each building elevation performs a different role. The southern louver wall diffuses all direct sunlight and reflects light deep into the building's interiors. The northern wall reflects direct sunlight that enters through a skylight, and floor setbacks around the atrium allow the brightness of the sky to light each floor.

The project's south-facing walls were specially designed for view and solar shading. As the students describe, “Through the use of an obstruction diagram and solar calculator, an egg-crate shading device specific to each façade was designed. The egg-crate-type louver devices block all direct light and also bounce light further into the space. The shading device is outside the building envelope, reducing direct solar gain.”

The louver system designed for the structure's north wall “prevents glare by blocking views of direct sunlight.” The students further explain, “Each louver is parallel to the lowest angle of the sun that would ever hit its location on the wall. The louvers are overlapped so no one in the space is able to see the direct light on the wall's surface. The shape of the louver diffuses light, bouncing it into the space, and the curved shape creates a dynamic play of light across the wall's surface.”

To achieve a balanced lighting effect, the students also coordinated the integration of electric lighting. To achieve this, “the electric light is photosensor-controlled on a digitally addressable lighting control system.” Library stack fixtures are also on a motion-sensor-controlled system, and reading lamps are “managed by the individual.” Through the use of these three primary daylighting techniques, “an overall minimum of 40 footcandles is maintained throughout the library.”