Architects: MMC International Architects
Role: Structural engineering and structural glass design
The Calgary Eaton Centre and TD Square, two adjacent shopping centres known collectively as ‘the Core’, are currently undergoing extensive renovations in order to update and revitalize the retail facilities. Located in downtown Calgary, the shopping centres occupy three city blocks, and feature walkways which span over streets to connect the second, third and fourth levels.
The renovation scheme features a number of striking architectural features, which combine to create a dynamic and enjoyable retail environment that will attract high-end tenants and draw increased numbers of shoppers to the mall.
One of the feature elements is an impressive skylight that continuously spans the three blocks covered by the mall without visible expansion joints. Shaped as a barrel vault, and spanning 750ft long and 86ft wide, the skylight is hung from 95 tubular steel arches by stainless steel spider fittings with glass suspended below. This design solution effectively maximizes sightlines and visibility by minimizing visible structure. Comprised of more than 1800 insulating glass units, the glass roof covers an area of approximately 70 000ft², making it one the largest continuous skylights in North America.
This impressive glass roof combines the aesthetic with the practical by both flooding the retail space with natural light and providing maximum thermal performance.
Halcrow Yolles provided both structural engineering and structural glass design services for this remarkable structure. The firm applied its expertise in highly complex structural glass engineering and optimal building envelope performance with its thorough understanding of the programme requirements for functional, flexible and aesthetically pleasing retail environments to ensure that the client’s objectives for the project were met.
Engineering solutions developed for the project include:
- Reinforcement of the existing buildings to allow for the renovation and addition of the new skylight
- Design of a barrel vault skylight to continuously span all three buildings
- Development, in collaboration with Gartner Steel and Glass, of a custom spider fixing to ensure maximum adjustability which ensured efficient installation
- Design of the point supported insulating glass units to accommodate the required loads
- Determination of the optimal glass composition for excellent thermal properties
- Development of a cost-effective way to test the skylight for water tightness
- Utilization of a series of steel tube arches with structural glass suspended beneath to achieve maximized sightlines and visibility