Boston’s original Isabella Stewart Gardner Museum opened in 1903 at Fenway Court, a Venetian-style palazzo built by the patroness Isabella Stewart Gardner to showcase her substantial collection of over 2,500 works of fine and decorative art, including tapestries, furniture, manuscripts and textiles, from Europe, Asia, the Islamic world and America.

The Museum began as a showcase for Isabella Stewart Gardner’s collection of over 2,500 works of fine and decorative art, including tapestries, furniture, manuscripts and textiles, from Europe, Asia, the Islamic world and America.

The number of annual visitors has grown from 2,000 to 200,000. This increase, combined with new special events, began to detract from the original purpose of the rooms and their exhibits. To counteract this, the Museum launched an Extension and Preservation Project, commissioning sufficient extra space to return the palazzo’s rooms to their original glory.

The new extension sits elegantly in the museum gardens at a discreet distance from the original building, to which it is linked by a glass corridor. The four-storey building with its carefully restrained roofline is clad in glass and green panels of oxidized copper.

The extension is composed of four separate volumes linked by glazed circulation spaces including a grand central staircase. Each volume accommodates a different programmatic element of the museum. The largest of these is the 296-seat auditorium, which has three balcony levels arranged around a central stage, lit from above by a skylight. The second largest is the 2,000 sq ft special exhibition gallery, which includes an annexe gallery for light-sensitive objects. With an entire north wall of glass and a skylight with micro-louvers, light levels can be minutely managed to suit the diverse requirements of this new gallery space is well able to manipulate levels of natural light to its requirements. This flexibility is supplemented by the movable translucent ceiling, giving full scope to vary spatial conditions subject to specific exhibition requirements. The last and smallest two volumes contain administrative areas, conservation labs and support spaces for the performance hall.

These volumes ‘float’ above a wholly transparent ground floor, which is like an airy greenhouse looking out through the trees. This level is inhabited by classrooms, cafe and orientation areas.

Entrance to the Museum is made through the new entrance atrium on Evans Way, flanked along the street front by greenhouses that serve the Museum’s horticultural program, and above which are found the artist-in-residence apartments, addressing the park from beneath their sloping glazed roof.

LEED certification is ensured by the incorporation of a geothermal well system, daylight harvesting, water-efficient landscaping techniques and the use of vernacular materials.