Class In Glass: The Hotchkiss School

Centerbrook Architects has made a sweeping statement in glass with the new Katherine M. Elfers Hall in the Esther Eastman Center at The Hotchkiss School in Lakeville, CT. This new music pavilion is a dramatic addition to the school's older Walker Auditorium, a 1970s brick building, whose stage area was increased and improved as part of the overall project. Essentially a rectangular glass box, Elfers Hall was designed by Jefferson B. Riley, FAIA, partner at Centerbrook Architects, in Centerbrook, CT. Mark Herter of Centerbrook Architects served as project manager.

“The back of the main campus building faces a beautiful lake and hills,” notes Riley. “The school had turned its back to the lake, and part of their master plan was to recapture the view. That is the primary reason for the glass.” Riley adds that glass, when thick enough, has good acoustic properties and serves the concert hall well. In fact, Rolf Smedvig, the lead trumpet player for Empire Brass, stopped mid-concert on the opening night of the hall to congratulate the architects for “getting it right.”

Another attribute of the glass is that students from other departments, as well as people walking by the structure, can see in, making the music accessible, and hopefully, attractive to all. “This is a great venue for students to practice and perform music,” says Riley. “Why not be surrounded by Mother Nature?” At night, Elfers Hall is even more powerful and dramatic, with downlights grazing the glass walls and concert lighting sparkling from the interior of the rectangular hall with clipped corners.

“A different kind of building would have obscured the view to the lake,” explains theatre consultant Charles Cosler of Charles Cosler Theatre Design in New York City, who collaborated on the project. “So they built one you can see right through. Jeff Riley's design concept was to blur the boundaries between indoors and outdoors.” The steel frame that serves as an armature for the glass was left exposed and then coated with 27 layers of intumescent paint that expands when exposed to heat to help protect the steel. “By using steel in this way, and not building up fireproofing around it with sheetrock, there is a slimmer structural armature that is more see-through,” explains Cosler.

Upholstered wooden pews, with fabrics in shades of blue and green, rather than traditional theatre seats, are arrayed on two levels of the 715-seat space: an orchestra level that embraces three sides of the stage; and a balcony level that wraps all the way around the back of the stage. “The upper level can be used for seating or as a choral balcony,” says Cosler. There is also a flat floor in front of the stage that can be filled in with loose chairs for performances or tables and chairs for special events. An interesting architectural feature is the balcony balustrade, created of curving wood shapes and patterns that animate the space and let light and sound pass through.

Flush with the stage floor level, there is a small lift that stops at house level and goes down to the basement. It can be used to move the loose chairs, a piano, or scenery. One important factor for Cosler is the ability to roll scenery or equipment from the Walker Auditorium stage to the new music center stage. “This is a major parameter I set at the beginning of the project,” he says. “It was important to make sure the two stages were at the same level, with a door opening between them. In fact, the stages are virtually back to back.”

Lighting is primarily concert and architectural, with ETC Unison architectural control and an ETC dimmer-per-circuit system installed as a provision for future theatrical lighting. So for now, there is white downlight provided by Altman 1kW Fresnels and frontlight from ETC Source Four® ellipsoidals. “There is an ETC system next door in the Walker Auditorium,” Cosler points out. “If need be, they can bring the console over for control of the system.” The systems integration was done by Barbizon New England (Woburn, MA), who also supplied the lighting equipment.

As part of the overall project, Pook Diemont and Ohl (Bronx, NY) installed a new double purchase rigging system in the Walker Auditorium during the project as a means to increase the wing space there. “They have a small stage area, and by moving the rigging to the fly floor level, they can walk underneath and have extra space stage right,” Cosler notes.

Combined, the existing auditorium and new music pavilion create a spectacular venue for the students. “The goal for the new space was to provide a proper facility for an expanding music curriculum at the school,” says Cosler. “I think the environment achieved for listening to music is absolutely splendid, from the site to the glass box to the seating wrapping around.” Cosler also points out that the acoustics, by Gerald Marshall of Marshall/KMK in Chappaqua, NY, are “fabulous.”

As Marshall explains, “world-class concert hall acoustics were a high priority in the design process.” The classic rectangular shoebox shape, the high ceiling, and even the glass walls contribute to the good acoustics. “Glass is a very hard, dense, and impervious material,” says Marshall. “That's why we like it for reflectivity.” On the first and second levels of the three-level structure, the glass panels are set in a zigzag design to help diffuse the sound in the hall.

To add flexibility to the acoustics, there are large draperies that hang above the array of ceiling panels. The curtains are motorized and can be retracted into storage pockets. There are also motorized vertical curtains on the windows. “Large groups can get loud in a small hall,” notes Marshall. “The curtains can reduce both loudness and reverberance.” In addition to the curtains, the reflective ceiling panels have absorptive materials on top to control reverberation. “At the owner's discretion, that absorptive material can be removed to any extent desired, if a more reverberant hall were preferred,” Marshall adds.

For amplified performances, an audio system designed by Tom Knauss of Marshall/KMK, was installed by North American Theatrix in Waterbury, CT, to make the room and surrounding outdoor terraces as flexible as possible. Equipment includes a portable Crest XR20 console, an “exploded” cluster of JBL PD series loudspeakers with JBL Control series boxes for under-balcony fill, BSS digital processing, QSC CX series amps, and a Telex communications system.

The architects met various design challenges including a pathway to the new space from the existing building, which resulted in a natural, gentle curve past the classrooms and practice studios. Since the school's original building is Georgian in style, the idea of the glass evokes the conservatory of a Georgian home. “We have one foot in the past and one in the present,” says Riley. The ultimate design has clean lines and a contemporary feel, with the glass opening to the outside to let the music float out of the pavilion and out over the lake.


Jefferson B. Riley, FAIA, Centerbrook Architects and Planners

Theatre/Lighting Consultant:

Charles Cosler, Charles Cosler Theatre Design, Inc.

Acoustic, Sound System Consultant:

L. Gerald Marshall, FASA, Marshall/KMK Associates, Ltd.


Pook Diemont & Ohl

Lighting Equipment & System Integration:

Barbizon New England

Sound Equipment & System Integration:

North American Theatrix