Equipped for lectures, film screenings, and musical performances, the lower-level auditorium features a baffled ceiling, cherry paneling, and large clerestories — the latter made possible by the ground plane that slopes away from the building.
An open, skylit stair descends from the winter garden to lower-level offices, two new classrooms, and a 180-seat auditorium.
The new north addition is a glass-enclosed lobby space that serves as the museum's main entrance. Charlotte, N.C.–based artist Tom Schulz was commissioned to create a custom concrete finish for the plaza, which involved staining large square sections and scoring the surface.
The new glass-front lobby has expanded ticketing and waiting areas, as well as a museum store. Nestled between two 1982 Hardy Holzman Pfeiffer–designed pavilions, the new north addition retains the pavilions' brick façades and columns so that visitors are aware of the boundary between new and older spaces.
The south façade of the new addition is clad with a terra-cotta rainscreen and custom glass by Viracon. The finishes are designed to complement the materials in the original structure, while providing protection from harsh ultraviolet rays in three new galleries, a requirement for many traveling exhibitions.
The center gallery in the south addition is one of three new exhibition spaces. Floor-to-ceiling glass panels separate it from the noise of the winter garden while still allowing in daylight.
The museum's gallery spaces were designed to be minimal so as not to detract from the artwork, and feature neutral-colored walls, cove lighting, and wood floors. The façade treatment (alternating glazing and stone or terra-cotta) allows visitors to get glimpses of daylight as they walk between galleries.
A canted skylight connects the roof of the original museum building to the lower roof of the south addition in the winter garden. Unlike the central skylight, these panels are clear glass, allowing sunlight to wash across the 1929 façade.
The original 1929 façade is preserved in a winter garden linking the south addition to the existing structure. Used as an event space, a café, and a welcome daylit respite from hard New Hampshire winters, the space features a large central skylight that contains two layers of perforated stretch vinyl fabric from NewMat, which help to cut down on glare and dampen the reverberant acoustics.
Opposite the historic façade in the winter garden are two large Sol LeWitt murals — designed just before his death in 2007 — that frame the view into the central gallery in the south addition.