This ambitious urban redevelopment project will see a new 24-storey office tower constructed on a 50×120 foot site within the façade walls of an existing 3-storey stone and timber heritage building, right in the heart of Granville Street. Working within the standards and guidelines for the Conservation of Historic Places in Canada, the project will retain and conserve the existing façade, while providing an additional 123,000 square feet of Class A office space above.

Project Essentials

  • LocationVancouver, BC
  • ClientBonnis Properties
  • ArchitectPerkins&Will
  • Size129,200 ft² (12,000 m²)

Building a 335-foot-tall-tall tower on such a narrow site required a creative structural engineering response. In this case, the traditional concrete core was replaced with a lighter and more carbon-friendly steel diagrid structure that frames all four sides of the building before narrowing as it passes through the 3-storey heritage portion of the building. This creates a rigid tube structure that is lighter than a conventional concrete core structure, resulting in lower seismic forces and less drift. The contemporary structure differentiates itself in its geometry, style, and materiality, and creates a dynamic aesthetic expression as the diagonal bracing can be read through the façade glazing.

The design’s heritage rehabilitation component also called for an innovative structural approach. To stabilize the stone façade structure, two horizontal steel ring trusses have been situated at the L2 and L3 levels. These trusses independently brace the façade and prevent it from experiencing larger seismic drift as the tower experiences sway deformations.

The final result will be a distinctive addition to Vancouver’s skyline; a sleek, modern office tower rising through the restored heritage façade, supported by a low-carbon structural frame with a striking architectural expression.

Renders: Perkins&Will