Located in Boston’s Financial District, this 32-story reinforced concrete structure with a travertine-clad façade was designed by noted architect Pietro Belluschi. The original façade design, while innovative, lacked adequate waterproofing details. Within a few years of completion in 1971 cracking of the travertine cladding had developed. The building had undergone several repair programs, addressing both the travertine and windows, but water infiltration and stone failure continued. BLA  developed a façade restoration and window replacement program that was completed in 2012. The project included extensive repairs to the travertine,  and wall flashing systems, and a window replacement program consisting of the installation of new high performance units in the original bronze frames (including federally mandated blast rated windows on the lower floors). The high performance glass package reduced energy consumption by 35%, reduced sound transmission, and improved interior lighting. The addition of green glass on the façade was lauded for its exterior aesthetics. The program also included replacement of the roofing systems, restoration of parapets and roof-level masonry structures, street-level plaza waterproofing and paving, leading to a modernization in efficiency that retained the integrity of the building’s historic provenance.