Keystone Building, 99 High Street
Exterior Restoration and Window Replacement / Facade Consulting
Boston, MA / Completed 2012
Located in Boston’s Financial District, this 32-story reinforced concrete structure with a travertine-clad façade was designed by noted architect Pietro Belluschi, in collaboration with Emery Roth & Sons. The original façade design, while innovative, lacked adequate waterproofing details. Within a few years of completion in 1971, water infiltration and cracking of the travertine cladding was had developed. The building had undergone several repair programs, addressing both travertine and windows, but water infiltration and stone failure continued to plague the structure.
Bone/Levine Architects developed a façade restoration and window replacement program that was completed in 2012. The project included extensive repairs to the travertine, a retrofitted flashing system, and a window replacement program consisting of the installation of new high performance units into the original bronze frames. The windows, with a 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.