511 14TH CANADIAN CONFERENCE ON BUILDING SCIENCE AND TECHNOLOGY TORONTO CITY HALL WINDOW RETROFIT: CONVERSION OF SINGLE GLAZED WINDOWS TO A DOUBLE GLAZED SYSTEM ON A HERITAGE BUILDING R. Wood ABSTRACT From 2009 to 2012, over 1200 replacement windows were designed, fabricated and installed at Toronto City Hall. The original, single-glazed windows were replaced with energy efficient, sealed units. The scope included preliminary design of a lock strip gasket system, a stainless steel frame, and an aluminum frame. Interior and exterior glazed options were considered for each. Wind tunnel testing was completed to determine the wind loading criteria. Given City Hall’s designation as a heritage building, all changes had to be approved by Heritage Preservation Services. No parts of the historic building fabric could be removed, the new system had to be reversible, and the overall appearance had to remain consistent. The alternatives were evaluated on Health and Safety, Heritage, Capital Cost, Lifecycle Cost, and Technical Performance. A custom, stainless-clad, aluminum frame system was selected. It harnesses the structural and performance benefits of extruded aluminum systems, while respecting the original architect’s use of stainless steel. The exterior contains a pressure-equalized, drained cavity to provide optimal performance. A comprehensive quality control program was developed. Full scale replicas of the existing system were used for testing, training of glaziers, and exploration of improvements to the design and installation. Material and workmanship were regularly reviewed through production, fabrication, and installation. Finally, a rigorous in-situ testing program was implemented. Due to the complexity of this type of project, close collaboration among all members of the project team was crucial to a successful outcome. Integrating the architectural, engineering, fabrication, and installation teams from the onset of the project enabled numerous improvements in process and design. These improvements resulted in significant capital cost savings for the client, a higher performing window system, and on-time completion. Temperature regulation complaints have decreased significantly and reports of condensation or frost on the interiors have been eliminated. INTRODUCTION Toronto City Hall was officially opened in 1965. In 2009, C3 Polymeric was awarded the contract to undertake the design and replacement of 780 original windows on the east tower. They were to be replaced with energy efficient, double pane units. Not only were the existing windows stained, but occupants complained of discomfort due to inconsistent temperatures in their working environment. This had negative impacts on both energy efficiency and employee productivity and morale. The original City Hall design by Finnish architect Viljo Revell was the winning entry of an International Design Competition for a new Toronto City Hall. City Hall is an established landmark and tourist destination. It was listed as a heritage property in 1976, and officially designated in 1991. In undertaking the retrofit, the architectural significance and heritage designation of the building required consideration.
10
Embed
TORONTO CITY HALL WINDOW RETROFIT: CONVERSION OF SINGLE ...obec.on.ca/sites/default/uploads/files/members/CCBST-Oct-2014/B6-6... · TORONTO CITY HALL WINDOW RETROFIT: CONVERSION OF
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
5 1 1
14TH CANAD IAN CONFERENCE ON BU I LD ING S C I ENCE AND T E CHNOLOGY
TORONTO CITY HALL WINDOW RETROFIT:
CONVERSION OF SINGLE GLAZED WINDOWS TO A DOUBLE
GLAZED SYSTEM ON A HERITAGE BUILDING
R. Wood
ABSTRACT
From 2009 to 2012, over 1200 replacement windows were designed, fabricated and installed at Toronto City
Hall. The original, single-glazed windows were replaced with energy efficient, sealed units.
The scope included preliminary design of a lock strip gasket system, a stainless steel frame, and an aluminum
frame. Interior and exterior glazed options were considered for each. Wind tunnel testing was completed to
determine the wind loading criteria.
Given City Hall’s designation as a heritage building, all changes had to be approved by Heritage Preservation
Services. No parts of the historic building fabric could be removed, the new system had to be reversible,
and the overall appearance had to remain consistent.
The alternatives were evaluated on Health and Safety, Heritage, Capital Cost, Lifecycle Cost, and Technical
Performance. A custom, stainless-clad, aluminum frame system was selected. It harnesses the structural and
performance benefits of extruded aluminum systems, while respecting the original architect’s use of stainless
steel. The exterior contains a pressure-equalized, drained cavity to provide optimal performance.
A comprehensive quality control program was developed. Full scale replicas of the existing system were
used for testing, training of glaziers, and exploration of improvements to the design and installation. Material
and workmanship were regularly reviewed through production, fabrication, and installation. Finally, a
rigorous in-situ testing program was implemented.
Due to the complexity of this type of project, close collaboration among all members of the project team
was crucial to a successful outcome. Integrating the architectural, engineering, fabrication, and installation
teams from the onset of the project enabled numerous improvements in process and design. These
improvements resulted in significant capital cost savings for the client, a higher performing window system,
and on-time completion. Temperature regulation complaints have decreased significantly and reports of
condensation or frost on the interiors have been eliminated.
INTRODUCTION
Toronto City Hall was officially opened in 1965. In 2009, C3 Polymeric was awarded the contract to
undertake the design and replacement of 780 original windows on the east tower. They were to be replaced
with energy efficient, double pane units. Not only were the existing windows stained, but occupants
complained of discomfort due to inconsistent temperatures in their working environment. This had negative
impacts on both energy efficiency and employee productivity and morale.
The original City Hall design by Finnish architect Viljo Revell was the winning entry of an International
Design Competition for a new Toronto City Hall. City Hall is an established landmark and tourist destination.
It was listed as a heritage property in 1976, and officially designated in 1991. In undertaking the retrofit, the
architectural significance and heritage designation of the building required consideration.