Development of the airspace above the southbound tracks has been delayed several times. The building was conceived by Tufts president Jean Mayer, who foresaw an "epicenter of high-profile medical research" in downtown Boston. In 1991, Tufts created a for-profit development subsidiary, TUDC LLC, and acquired the rights to the airspace. Development over the past decade has been complicated by Boston waterfront zoning restrictions, which require pedestrian access to the waterfront. In 1997, TUDC brought on Hines Interests LP as a development partner. In 2006, TUDC and Hines filed a Development Plan for the project.