Built in 1947 in the Collegiate Gothic style, the iconic 150,000 sf Dillon Gymnasium is located on a prominent site at the heart of Princeton’s campus. Previously home to all varsity athletics, the current Dillon Gym currently hosts all campus recreation programming for the University, serving undergraduate and graduate students, faculty, and staff. Despite a series of renovations and upgrades since the building’s original construction, accessible routes to program areas remained limited and often compromised. The existing space dedicated to general fitness was limited and disconnected from main circulation routes. Key spaces inside and outside of the building were dramatically underutilized, including unused squash courts and prime exterior space that was occupied by modular structures. This unique adaptive-reuse and expansion project creates a hub of campus wellness that transforms the center of campus into an inclusive space for the entire University community.

The main level of the new addition stands apart from the existing masonry building, as a singular room on top of a masonry plinth with panoramic garden views. During the day, users enjoy long vistas of the campus or take in the tranquil roof gardens. A combination of perimeter glazing, skylights, and punched windows welcome ample natural daylight into each space, and operable components of the façade bring in fresh outside air. At night, the addition transforms into a vibrant marker of campus recreation, illuminating the flurry of activity that extends late into the night.

The renovation and expansion of Dillon Gymnasium was motivated by a need for new, enhanced, and accessible facilities for an increasing student population. The design brief called for a new 40,000 sf addition and renovation of less than 10,000 sf. During concept development, the design team discovered key areas of existing space that were underutilized, predominantly 16 squash courts, which could be repurposed, thus decreasing the amount of new construction required. With this creative programming approach, the area these courts occupied will serve as the main entrance, reception area, primary fitness equipment space, and the connection to a modest 14,200 SF addition that is far better contextualized within the campus.

Key to the sustainability story is a 65% reduction in new construction compared to the original brief through creative adaptation of existing spaces. This substantial reduction yields immediate savings of embodied carbon and long-term operational carbon. Specific sustainability features include: use of mass timber; automated operable windows for natural ventilation; attention to natural light and views; and visual connections to landscape and intensive green roofs.

Dillon Gymnasium was built upon the remains of the 1903 University Gym that burned in 1944. Due to the legacy of the previous structure and a sloped site condition, the existing gym building comprises multiple offset stories of predominantly inaccessible spaces, and no accessible main entrance. A main priority of renovations is to create access for all — thus, the main entrance was relocated, creating a new welcoming and accessible main entry and social heart of the building.