The transformation of the former Union Train Station, once a landmark of Ottawa, into the current home of the Senate of Canada, represents a unique intersection of heritage preservation and material innovation. The project’s objectives included the restoration of the Beaux-Arts station’s grandeur and the building adaptation for modern use while expressing a renewed narrative of Canadian iconography through design.

One of the defining characteristics of Canadian Gothic architecture, evident in Parliament’s Centre Block, is the rich elaboration of natural forms, seen in the carved details of flora and fauna, all executed by skilled artisans.

In contrast, the Beaux-Arts classicism of the former train station is defined by mathematics, geometric symmetry and classical orders as markers of its architectural language. 

The gothic lends itself to uniqueness, ornamentation and asymmetry, often characterized today as ‘custom’ or ‘bespoke’ work, while the Beaux-Arts lends itself to repetition and mass production typical of the industrial era in which it emerged. 

It is within these contexts and precedents that a design response developed that synthesized elements of both these worlds. The solution developed by merging traditional and digital fabrication techniques, one closer to Gothic sensibilities, the other more attuned to Beaux Arts techniques, the result being something more than either. 

The project successfully introduced a uniquely Canadian narrative into the design, one that speaks to Canada’s evolving identity while honouring the nation’s diverse landscape and shared history. 

Exterior Transformation  

Originally built as a ‘fabric’ building at the termination of a long urban block, the site now exists as a pavilion, independent of any other buildings. Currently connected by intersections and pathways, it contributes once again to the public and urban life of the City.

The new east addition resolves a long-unfinished and abandoned elevation—once a party wall—completing the building’s exterior for the first time in decades.

Combined with the completion of the north east cornice, the contemporary addition takes its cues from the existing Beaux-Arts west façade composition, reinforcing the building’s original seven-bay rhythm framed by six columns. Innovations in building technology allowed for limestone cladding to be partially laid on a precast base, and subsequently finished in situ, resulting in a finished elevation solution to traditional load bearing stone assemblies. The result was a significant reduction in construction time. 

Heritage Preservation and Adaptation

Originally constructed in 1912, the building required rehabilitation to accommodate the needs of the Senate after having undergone nearly a century of renovations. The former train station was converted in the 1970’s into The Government Conference Centre and many of the subsequent additions and renovations were poorly executed or inconsistent with its historic character. The building also required a complete overhaul of all major building systems as well as compliance with current seismic requirements and life safety upgrades.

The Senate of Canada creates a contemporary language of new volumes that complement and juxtapose the classical language of the original building.

The Senate Chamber and the committee rooms are carefully calibrated architectural insertions into the existing building’s great rooms. Carefully detailed they are also intentionally simple in their volumetric expression and sit as pavilions within the larger heritage spaces. These insertions re-establish the original Beaux-Arts axial symmetry along a processional route.

Once the Senate returns to Centre Block in a decade or more, the building design accommodates different office configurations, as well as conferencing and meeting facilities. Over 90% of the construction costs were associated with reimagining the train station as a modern 21st-century office and meeting facility for the future, securing the building’s role for the next century.

A major conservation milestone was the restoration of the General Waiting Room’s plaster ceilings. The project employed heritage technologies never before used in North America to stabilize and preserve these delicate features. Additionally, structural reinforcement using thin Kevlar bands was introduced to support aging steel beams without compromising the integrity of the historic ceilings.

Canadian Heritage Elements

One of the key challenges was introducing new programming and spatial arrangements without compromising the integrity of the building’s monumental spaces. This was achieved by insertions of pavilion spaces within the larger monumental spaces and by retaining and making visible the original spatial and processional experience of the station. Efforts also focused on ensuring that new work was detailed in a way commensurate with both the sensibilities of the original train station and the craft-based elaborations of the original Senate in Centre Block.

This effort involved reinterpreting traditional bespoke processes through modern fabrication techniques, ensuring that craftsmanship could be achieved at scale without sacrificing detail or authenticity.  

To do so required a multi-disciplinary collaboration led by the architectural team.  Working both with Canadian artisans and fabricators led to an adaption of traditional techniques, such as wood carving, to the digital age. By iterating between physical mock-ups and advanced technologies, designers could experiment and rapidly prototype solutions, overcoming traditional constraints on expression and enabling more intricate, cost-effective, and scalable designs. 

Canadian Landscape in Bronze

Three large scale bronze murals define the elevations of the Senate’s Great Waiting Room, each depicting scenes of the Canadian landscape originally sourced from historic and contemporary photos. To realize these images, we collaborated with metal fabricators to produce a series of break-form panels with punched perforations. The team tested both stochastic and halftone patterns to make this iconic decorative backdrop. Once decided on a half-tone pattern, they began the process of stamping sheets and determined the best surface finishes to maintain image clarity.

While perforating metal is a common practice, the use of bronze – a much softer material – was unique to this program and required a much more extensive and modified process from the fabricators. The team also experimented with patination, providing a final finish that maintained the resulting piece in a hue and sheen that complements the surrounding elements.

Measuring 14m long by 6m tall, these soaring bronze panels place iconic Canadian landscapes on full display, providing continuity to Centre Block’s history of storytelling and the increasing presence of Canadian motifs inspired in the decorative elements of the building

Making virtue out of necessity, the technical resolution of these images satisfies both acoustic and mechanical requirements. 

Maple Leaf Carving

Collaborating with the Dominion Sculptor of Canada, what would ordinarily take decades to realize as unique, manual sculptural reliefs seen throughout Centre Block in glass and wood were realized here through a process that embraced both digital fabrication and manual composition.

The process began with ten hand-carved maple leaves representing the diverse indigenous species found across the country. Important to this process was the register of the Sculptor’s hand in each piece – seeing the chisel marks that gave expression to each leaf. The drawings were then 3D scanned, generating high-resolution stereo-lithography (.STL) data for CNC machining. Initial prototypes were crafted in foam and walnut panels before digital elevations were designed for the principal doors of the Senate Chamber and key committee rooms.    

The final pattern embraces a natural, random arrangement reminiscent of the artisanal craftsmanship of Centre Block. Once the proof of concept was validated, the scans were sent to a millwork fabricator for testing in solid walnut.

The leaves also feature in a kiln-fired decorative cast-glass wall separating the chamber from the antechamber. Two layers of glass create an illusion of depth and an offset pattern. 3D-printed foam molds, based on the original hand carvings, were used to create ceramic molds for casting. These molds allowed a unique layout across twenty- two panels, using multiples of ten leaf profiles. Throughout the casting process, architects remained actively involved, refining the design as each piece emerged from the kiln.

Pinecone Pilasters

Inspired by carvings found within the Centre Block Chamber, a pinecone figure appears numerous times, each in its unique, idiosyncratic form. Examining the pinecone’s geometric structure, described mathematically as a Fibonacci Spiral Phyllotaxis, many iterations of this form were modeled from several orientations, and through the play of light on a convex and concave figure. This began with three-dimensional printing of the shapes, then full-scale two-dimensional printed views, and finally CNC wood mock-ups for the pilasters. 

Senate Throne and Canadian Flag 

The Senate Throne is composed of white marble extracted from a unique quarry located on Vancouver Island. Working with the quarry, we identified several stone blocks, documenting each face to establish possible book-matching could be created on the finished elevations. The stones were than mapped to each surface of the throne. Through this process, the drawings reveal a close match to the final results. 

Situated to either side of the Senate chamber’s throne, two large wall carvings in walnut were created from imagery of the Canadian flag.

To create the illusion of the undulating fabric, colour, and shading, we worked with Carlton University’s architecture program to develop a tooling path algorithm that would render these effects through inflections in the 5-axis CNC milling path. This eliminated the need for any special staining or topographic modelling, relying instead on inflections of the tool path as it cut into the walnut, capturing light in a manner similar to lenticular printing. This required some processing of the original photographic images we had captured to amplify certain effects, followed by a 3D modelling exercise to interpolate those effects, followed by a translation of that data into code for the CNC, and finally with the last step measuring the results by physical lighting the carved samples. This exhaustive, iterative process allowed us to control the appearance of the three-dimensional illusion. 

Conclusion

By revitalizing a failing resource, this project makes a significant contribution to public life and the urban landscape, just as the building once did when it served as the city’s main gateway as a train station.

The transformation gives powerful and persuasive proof of the inherent possibility for creative reinvention of historic architecture, with the whole being greater than the sum of its parts.

In joint venture with KWC Architects
Conservation Architect: ERA Architects
Sculptor: Dominion Sculptor of Canada, Phil R. White
Bronze Fabrication: MCM 2001
Cast Glass Fabrication: BermanGlass/Forms and Surfaces
Wood Fabrication: Carelton CIMS Lab
Wood Fabrication: Beaubois
Photography: doublespace photography, Tom Arban Photography Inc.