Heritage building restored to highest standards of environmental stewardship
Calgary, Alberta, Canada is a relatively young city, and the Calgary Public Building (CPB) is a significant heritage structure from 1929. The CPB is immediately adjacent to the public space created for the 1988 Olympics. It is located on Stephen Avenue, a designated pedestrian street with historical roots that runs through downtown. The CPB is a designated heritage building, which severely limits proposed changes to the building's exterior.
Currently, the first two floors serve as a premiere performing arts venue lobby. Originally, the building served as the main post office for Calgary; however, only small ‘quick fix' solutions have been done to keep it functional. The climate in Calgary is also quite extreme with temperatures reaching -30°C in winter months. As such, energy conservation, IAQ and future occupant comfort were key project concerns.
Before commencing, the Owner requested a comparison between renovating the building into AAA office space and abandoning the existing building to create new office space outside of the downtown core. The Owner chose the former and invested significant resources into the rehabilitation. The re-use continues to contribute to the vitality of the downtown.
To achieve the aggressive energy reduction required by the municipality, the design team researched, modeled and tested strategies through mock-ups and simulations for creating a second, extremely high performance envelope liner on the interior of the building. This strategy was critical to leaving the historically designated exterior completely intact. The new envelope liner also incorporates the building infrastructure and promotes open and adaptable future interior space.
The design also re-used many original architectural strategies in the building. A south facing u-shaped building with over 300 original windows were all made completely functional again for passive heating and natural ventilation. Full daylight modeling was performed during design: This meant service spaces could be located in areas where there was insufficient natural light penetration for office work. The building is now contemporary office space, and one floor is completely restored as a representative heritage floor.
The result is a unique and quantifiable cold climate case study demonstrating that heritage buildings do not have to be demolished to make way for "more modern, energy efficient structures". After a year of operation, total energy consumption has been reduced by over 50%. The project shows that heritage buildings can be successfully renovated to the highest standards of environmental stewardship without sacrificing cost, energy efficiency, preservation standards or aesthetics of modern office environments.