In 2021, Boszko & Verity and Superkül won the design-build competition to renovate the CN Tower’s Outdoor Observation Level. Working creatively and collaboratively with the construction lead and the entire consultant team, we delivered a fully accessible and completely reimagined interior and exterior experience focused on enhancing visitor experience — the first renovation to this level since the tower opened in 1976. 

Undertaking a revitalization of this iconic landmark challenged us to execute a major feat: create more indoor space within the existing footprint while working 1,200 feet up in the sky under extraordinary logistical and climatic conditions. To complete the work, our team hoisted up a new four-storey permanent maintenance gantry and attached it to the exterior of the tower’s uppermost observation level. This was the first time a structure of this kind had been raised from the ground using cables since the CN Tower was completed. 

The brief called for the introduction of more steeply angled glazing, a replacement of the glass floor, and a wholesale redesign of the usable interior floor space and the outdoor observation area. To achieve these objectives, we designed and installed a new perimeter enclosure system with movement connections that secure bespoke mullions engineered to accommodate the tower’s central-axis oscillation. We removed the exterior steel mesh cage that previously enclosed the outdoor terrace and obscured views, creating a tempered space that features sloped glass with mesh screens across the upper sections. New glazed partitions and doors comprise an airlock vestibule system that stabilizes airflow and wind pressure differentials, making it easy for people to circulate seamlessly between interior and exterior. All dimensions were constrained by stringent elevator cab and hoisting limitations, including those of the glazing and glass-fibre-reinforced concrete (GFRC) benches.

The revitalized Lower Observation Level features GFRC seating around the perimeter and two new “Tilt Zones” that allow people to lean over the city in an unprecedented way. All materials draw inspiration from an arboreal canopy and other natural elements — rocky surfaces, the reflective surface of water, the ripple of a breeze — to honour the tower as a monument to Canadian life and ambition. Inspired by the CN Tower’s radial geometry, the biophilic modular ceiling design marries aesthetics and function, with digitally fabricated fins that extend centripetally like the branches of a tree, drawing the eye outward. The oak-laminated phenolic panels lend warmth, while the fins discreetly integrate mechanical, life-safety, and AV systems within a vertically compressed space. The modular system enables straightforward removal and reinstallation for access and servicing. 

Our design integrates sophisticated AV components: a floor-to-ceiling immersive video wall featuring two 40 x 3.5 ft panoramic screens; three large-format interactive video displays with assistive listening via infrared loops concealed within the floor; and satellite speakers that provide even and distributed sound throughout the space. Running along the edge of the newly replaced glass floor, the video wall was designed to showcase Artmosphere, an immersive art program that features original works by Canadian and Indigenous artists.

We worked in close collaboration with an accessibility specialist to design beyond best practices and provide a deeply inclusive experience that supports a diverse range of visitors. The tower has received Gold Certification from the Rick Hansen Foundation in recognition of the meaningful level of accessibility it has achieved across its spaces.

Images: doublespace photography, Tom Arban, and Michael Davidson