AWARD OF EXCELLENCE – BUILDINGS St. Joseph Seminary

The new home of St. Joseph Seminary is on the Catholic Campus at 84th Street and 100th Avenue, a beautiful site overlooking downtown Edmonton.

Rev. Richard Smith, Archbishop of Edmonton, said at the outset of the project in 2007: “The Catholic Church thinks in hundreds of years.” That simple declaration helped shape the entire design.

The team set out to make a building with a sense of timeless permanence, reinterpreting traditional forms of church architecture – arches, buttresses, and side aisles – with modern materials.

In traditional church design the structure and the architecture are inseparable, created simultaneously by a master builder. Similarly, this design team took a highly collaborative approach, attempting to act in unison as a single master builder made up of many professional experts.

At the heart of the seminary, visually and spiritually, is the new chapel, a sanctuary created entirely with cast-in-place, fair-faced, visually exposed concrete. Chalk-white, self-consolidating concrete that was cast in a single massive pour, the chapel walls are 450 mm thick, 11 metres high, and have a visually exposed area of over 700 square metres.

The risks of casting nearly 350 cubic metres of a highly customized concrete mix – without construction joints – while achieving the highest possible levels of architectural finish were daunting. The entire project team – structural engineer, architect, interior designer, construction manager, formwork contractor, formwork supplier and concrete supplier – all worked together for 18 months to develop the methodology.

Literally every detail of the chapel was painstakingly thought out in advance: the size and location of every form tie; the type, size and orientation of every sheet of form ply; the development of specialized formwork details to create sharp 90° exterior corners without chamfers; special structural reinforcing for crack control; and countless test batches to confirm the best colour, texture and porosity of the concrete. Portions of the formwork were even lined with fabric to create a concrete that has a soft and tactile appearance.

Functionally, the massive walls of the chapel also serve to provide protection from the noise and vibration of the outside world, to regulate temperature through their thermal mass, to provide a long reverberation time for enhanced acoustical performance of the pipe organ, and to act as a simple white backdrop for coloured light filtering through seven historic stained glass windows.

Structural steel also plays a vital role in the reinterpretation of traditional church architecture. The narthex has intricately detailed structural steel, while its steel arches on the aisles reinterpret the flying buttresses of traditional cathedral architecture.

Outside, the 15 metre glazed bell tower supports a steel cross 7 metres high that can be seen for miles across the river valley.

The structural engineer coordinated closely with other engineering disciplines. For example, the columns of the bell tower act as ducts carrying warm air to the windows, eliminating the need for radiant heating that would be visually unappealing. Similarly, the girts around the narthex provide lateral stability to the exterior columns, support the floor-to-ceiling glazing, and conceal the radiant heating pipes.

Within the chapel, the rear wall is all glass with seven historic stained glass windows. This wall is framed with columns so slender they are hung from the roof so that they act in tension for improved stability.

Today the project stands complete, on budget, with a construction cost of $33.5 million dollars. cce