9:00 am - 10:00 am | Room: Pretium Room | Session Chair: Sarah Gray

Building Retrofits

Reimagination Of 400 University And 60 Bloor: Overcladding Retrofit Case Studies

Large scale building retrofit is a growing market that requires a paradigm shift to deal with the challenges of working on occupied buildings. This paper explores the overcladding method of façade retrofit. Case studies of projects at 400 University Avenue and 60 Bloor Street West in Toronto are used to illustrate this approach. These occupied towers in downtown Toronto were over thirty years old. Their original, single glazed facades were approaching the end of their lifecycle and required significant upgrades or replacement.

The objectives of the retrofits were: minimize air and water leakage, reduce energy demand, improve occupant comfort, and modernize the buildings’ appearance. The buildings were to maintain full occupancy throughout construction. 

Detailed investigations were conducted to assess the condition of the original systems. Anchors, framing, and transition seals were analyzed. Retrofit methods including refurbishment, recladding, and overcladding were evaluated. It was determined that the project objectives could not be met utilizing refurbishment. Replacement would have caused significant tenant disruption and exceeded the budgets. Overcladding was selected for implementation.

Iterative design processes were used to engineer custom overclad systems. Most of the original system components remained intact. The new, unitized frames were mechanically fastened to the original frames from the exterior, prior to removal of the original glazing. As limited laydown areas were available, and it was not practical to install cranes on site, the new systems were field glazed. Air seals were completed prior to removals of existing glazing, ensuring the interior was never exposed during construction. Interior work was scheduled outside business hours and included removal of original glazing and select frame components, anchor retrofit, and cladding the original frames. 

400 University was one of the first commercial window system overcladding projects in Canada. Energy savings of over thirty-five percent were achieved. Building operators report significant reduction in environmental complaints and improved ability to regulate interior temperatures. 60 Bloor achieved an energy reduction of more than twenty-five percent and LEED EB:O&M Gold certification. The building features a modern building envelope with over thirty-five percent greater daylight openings. 

Overcladding was a viable retrofit strategy that met project objectives. Given the reliance on existing components, careful investigation and analysis was required to identify all constraints. Collaboration among team members was crucial to the successful outcomes. Integrating the architectural, engineering, fabrication, and installation teams from the onset enabled improvements in process and design, and on time and on budget completion.

Rob Wood, P.Eng., C3 Specialty Glazing Solutions

Mr. Wood is the President of C3 Specialty Glazing Solutions, a leading provider of curtain wall retrofits on occupied commercial buildings, and a member of The C3 Group of Companies. At C3, he has overseen the retrofit of high rise office towers across Canada, including Toronto City Hall’s two office towers; 400 University Avenue in Toronto; and towers in Edmonton, Halifax, and Sudbury.

Rob is a graduate of the System Design Engineering program at the University of Waterloo. He has been with The C3 Group since 2001, and has held various management positions within the group. Rob is on the board of the Great Lakes Ontario Chapter of the Young Presidents Organization (YPO), and is a member of other organizations, including BOMA Toronto and the Professional Engineers of Ontario. He is an active speaker, having conducted seminars and presentations on curtain wall retrofit to OBEC, the OAA, and other organizations.