Sir John A. Macdonald Building, Ottawa

EXISTING BUILDING
UPGRADE AWARD WINNER

Jury comments:
Perhaps the most impressive aspect of this project is how the envelope and building systems upgrades have been so discreetly integrated into the heritage structure. Architecturally, the atrium ties together the old structure with the new addition, while incorporating daylighting and ventilation strategies. A very sensitive, subtle and sustainable retrofit.

This former Bank of Montreal [a 1932 RAIC gold medal winning and federally classified heritage building] has been rehabilitated and expanded to accommodate a state of the art conference facility for the House of Commons. It serves as a venue for official government celebrations, state dinners, meetings, as well as educational and ceremonial functions. The design approach restored the somewhat dilapidated former bank to its original glory and filled in the adjacent empty lot with a contemporary insertion that contains additional required meeting, service and security programme components.

The technical demands of the new use, including security, IT and AV upgrades as well as completely new mechanical and electrical systems had to be balanced with preservation and restoration of the heritage fabric. The decision to reuse the empty building as a new facility was in keeping with the Government of Canada’s strategy to repurpose existing building stock rather than discarding and building new. The challenge was to rehabilitate the building in a manner that would ensure another 80 years in its new function while at the same time respecting its importance as an icon of Canadian Architecture. While the existing material pallet of the heritage bank had stood up well over the intervening years and became a basis for the future expansion, the mechanical system was not adequate to contemporary standards and significant improvements were pursued including connecting to the Cliff Street district energy plant and using the natural stratification of the tall public spaces for efficiency and comfort.

Heating and cooling needs are moderated by the thermal mass of the existing building and the new stone addition. These energy needs are further reduced by the installation of a new mechanical system featuring radiant cooling, coupled with displacement ventilation for the heritage bank. Given the 10-fold increase in the potential visitor population of the bank hall a significant increase in fresh air and cooling was anticipated and it was a challenge to achieve without negatively impacting the heritage context. The radiant cooling strategy offsets the impact potential of television lighting and assembly occupancy. The existing window radiator enclosures are reused as air supply locations and supplemented by diffusers concealed in benches located around the perimeter. These benches also conceal the valve controls for the new hydronic tubes incorporated in the floor assembly.

The natural stratification of the tall space is used to advantage with the old supply air grilles at the top of the space transformed into return air collectors. In addition to restoring and rehabilitating the existing building, all new materials were selected to match the same noble qualities and high durability standards of the existing building including bronze, Canadian marble, local limestone, granite, low-iron glass and walnut. Where materials were removed they were refurbished and reused including heritage light fixtures, limestone cladding from the demolished annex reused as cladding on newly exposed portions of the existing building, as well as the marble teller’s counter reused as benches and counter tops throughout the complex. Originally mandated to pursue a target of three green globes the project received the top rating of five Globes in the Green Globes rating system.

Project Credits
Owner
Public Works and Government Services Canada
Architect
NORR Architects & Engineers in association with MTBA Associates Inc.
Structural Engineer
John G Cooke Engineers
Mechanical Engineer
NORR Limited
Electrical Engineer
NORR Limited
Commissioning Agent
WSP Group
Civil Engineer
Trow Engineering
Landscape Architect
Planier
General Contractor/Construction manager
EllisDon
Photos
Doublespace Photography

Project Performance
Energy intensity
214kWh/m2/year
Energy intensity reduction relative to reference building under MNECB Version 1
21%
Potable water consumption from municipal sources
n/a
Reduction in potable water consumption
38%
Regional materials (as defined by LEED) by value
>20%
Reclaimed and recycled materials content by value
>20%
Construction materials diverted from landfill
>70%

Suppliers: Sloan plumbing fixtures, Altex roller shades, Masonite Architectural [Baillargeon Doors].

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