*The following article was originally published in the Toronto Canada Green Building Council Focus Magazine.

By Matthew Smith M.A.Sc., P.Eng
Engineer, Entuitive

Introduction

Climate change is introducing today’s buildings to ever more strenuous natural hazards, as well as creating uncertainty in the design process over how best to approach these changing demands. Designing buildings that are sustainable, in that they better protect their interiors from the elements, have a lower reliance on energy and external resources in general, and re-use and re-adapt existing materials, in turn allows these buildings to foster more resilient operations that are less susceptible to the effects of climate change. The following case studies are just two examples of projects in the Greater Toronto Area where structural and building envelope considerations in collaboration with a like-minded team contributed to a sustainable and innovative building.

Daniels Faculty of Architecture

Located at the historic One Spadina Crescent, the new Daniels Faculty of Architecture, Landscape and Design (DFALD), designed by NADAAA with Adamson and Associates serving as Executive Architect and E.R.A. Architects as Heritage Architect, presented a unique sustainability challenge both from a building envelope and a structural perspective. Phase One of the project was the rehabilitation and retrofit of the existing historic building, formerly Knox College, which ties into the adjacent Phase Two new construction.

The first challenge was the adaptive re-use of existing materials to suit the new structural and building envelope demands placed on the building. Structurally, historic mass timber trusses throughout the existing building were assessed for their capacity and generally reinforced for new loads and new spans.

The original convocation hall has been converted to a series of student spaces with exposed timber trusses and structural steel reinforcing where required. (Image courtesy of NADAAA (left); John Horner (right))

From a building envelope perspective, the challenge was upgrading the envelope to meet current performance goals while respecting the historic context of the existing architecture. The envelope of the existing building was “buttoned up” throughout, while extensive coordination and mock-ups of windows ensured the gothic revival architecture was maintained and still had concealed, modern detailing. Moving the envelope of the building from the floor of the attic up to the gabled roof allowed for a fully conditioned and partially occupied attic space while also improving the performance of the building. Phase Two of the building incorporates extensive areas of green roofs which can also be accessed by students.

The upper floor of the new building is dedicated to reconfigurable studio space. Key to the aesthetics and energy efficiency of this space was opening the roof to provide natural daylight throughout. This was achieved through an intricate structural steel roof of “bow-tie” trusses with glazing within the webs of the trusses. These trusses thus serve to meet the sustainability goals of the building while also achieving world-class architecture. The Daniels Building received the Canadian Institute of Steel Construction Award of Excellence, an achievement which the grand roof surely contributed to.

Left: exposed structural steel roof trusses (Photo by Peter Maccallum; Courtesy of the Daniels Faculty or Architecture, Landscape and Design); right: finished ceiling (Image courtesy of Jogn Horner)

York Region Administrative Annex

(Rendering by WZMH)

North of Toronto in Newmarket is another sustainable and resilient building under construction. The York Region Administrative Centre Annex designed by WZMH Architects will be an eight-story building that houses York Region’s public services and a Provincial Offences Act courthouse. The building has been designed to ensure the highest interior quality for guests and employees while being highly energy efficient. Central to the building is a full-height atrium framed in green walls and a feature staircase.

While flooding is often a hazard associated with coastal areas, local topology and hydrology can make it a risk in many areas. Such is the case for York Annex, located within the Western Creek floodplain and directly adjacent to a creek. Extreme flood scenarios have been modelled and show that flood waters can rise to just a few meters below the first floor of the Annex. Foundation walls adjacent to the river have been designed to be water-tight even during the worst-case flooding. A pedestrian bridge crossing the creek has piers that would be submerged during extreme flooding and have been checked for impact loading from floating debris, as have the foundation walls. Lastly, a standalone back-up generator building adjacent to the Annex and away from potential flood areas increases the resilience of the Annex.

Construction progress (Photo by Kay Lee)

Closing Remarks

The above two case studies have briefly demonstrated how sustainability and resilience can be incorporated in new and existing buildings, a mindset we must incorporate in all our projects given the ever-changing climate around us. The existing building stock in Canada and abroad represents a huge opportunity for sustainable retrofits which can be done efficiently and discretely. In today’s market, resilience is a key driver for buildings to attract quality tenants as they become increasingly aware of the risk climate change poses and how these can impact their business if not proactively considered. These case studies have focused on the structural and building envelope aspects of the projects, however resilience is not something can be achieved by any one consultant. The teams on both projects collaborated from the onset to ensure resilient and sustainable solutions were implemented throughout and across disciplines.