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Ken Soble Tower

Ken Sobel Tower viewed from air
Ken Soble Tower concept illustration
Ken Soble Tower concept illustration
Ken Soble Tower courtyard
Ken Soble Tower concept illustration of energy efficiency
interior view of unit in Ken Soble Tower
wayfinding panel at Ken Soble Tower
view of Ken Soble Tower from the ground looking up

Ken Soble Tower

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The Ken Soble Tower Transformation is a ground-breaking project rehabilitating a post-war apartment tower in Hamilton, Ontario. The achieved goal meets Passive House standards to reduce greenhouse gas emissions by a staggering 94% and lays the groundwork for industry-wide, ultra-low energy retrofits needed to maintain and upgrade thousands of apartments across Canada.

“Ultra-low energy retrofits that maintain affordability are not only possible, but critical to preserving and enhancing housing across the country. ” –Graeme Stewart, ERA Architects

Built in 1967, the Ken Soble Tower is the oldest high-rise multi-residential building in CityHousing Hamilton’s portfolio and has been in decline for several years. After considering several options including sale, rebuild, capital repair, and rehabilitation, CityHousing opted to retrofit the building, making significant improvements at a fraction of the cost of a new build. One of the first of its kind in North America, at 18 storeys and more than 80,000 square feet, the Ken Soble Tower is the largest EnerPHit certified residential retrofit project in the world. The building’s rehabilitation has modernized 146 units of affordable seniors’ housing while both reinvigorating community spaces and outdoor gathering areas and planning for aging-in-place, barrier-free living, and a changing climate.


Project overview: Envelope (R38 Overcladding; Passive House Windows; Juliette Balconies); Systems (Centralized HVAC with Cooling; Riser Replacements for Most Systems; Full Building Sprinklering); and Modernization (Accessibility Upgrades; New Community Room and Solarium; Interior Upgrades).


The Ken Soble Tower is one of the most ambitious social housing transformations in the country, paving the way for the nation’s aging housing supply to secure a healthy, resilient future for millions of Canadians. It will also lead Hamilton’s West Harbour revitalization, shifting the conversation from affordable housing as a liability to affordable housing as a district landmark.

Quick Facts:

  • Located at 500 MacNab Street North, Hamilton, Ontario, Canada
  • 146 units of modernized affordable seniors’ housing
  • Completion in 2020
  • Ultra-low energy use:
    – 94% reduction of greenhouse gas emissions compared to the existing building
    – At its peak, the total energy needed to heat or cool each unit will be equal to the energy needed to run 3 incandescent light bulbs (100W).
  • Designed for a changing climate: Using 2050 temperature projections to test thermal comfort in all seasons.
  • The building demonstrates passive resilience to extreme conditions: In case of failure of active systems, the building will stay warm in winter for up to two days (compared to 2 hours in a typical building) and below dangerous heat levels in summer for up to four days (compared to half a day in a typical building).
  • More than 20% of units will be barrier free. All common areas, outdoor gathering spaces, and circulation routes will be accessible and designed for aging in place.
  • EnerPHit certified! Read the press release for more details.

Project Team:

  • Owner: CityHousing Hamilton
  • Lead Architect: ERA Architects Inc.
  • Landscape Architect: ERA Architects Inc.
  • Mechanical Engineer: Reinbold Engineering Group
  • Building Envelope and Structural Engineers: Entuitive Corporation
  • Passive House Consultant: Transsolar, JMV Consulting
  • Electrical Engineer: Nemetz (S/A) and Associates Ltd.
  • General Contractor: PCL Construction

Download the information packet on the Ken Soble Tower.

Ken Soble information packet main page


City of Hamilton
Reinbold Engineering Group (mechanical engineer), Entuitive Corporation (structural engineer)
Transsolar & JMV Consulting (passive house), Nemetz (S/A) and Associates (electrical engineer)
Graeme Stewart/Ya’el Santopinto


  • Hamilton Urban Design Awards: Civic Achievement, 2021
  • Toronto Construction Association (TCA): Best of Best Awards: Project Achievement, 2022
  • EIFS Council of Canada (ECC): Architectural Design Awards Grand Prize, 2022
  • Canada Green Building Council (CaGBC) Awards: Green Building Excellence: Deep Carbon Retrofit, 2022
  • Engineering News Record (ENR): Global Best Projects: Best Green Project, 2022
  • Urban Land Institute (ULI): Terwilliger Center Award for Innovation in Attainable Housing, 2022
  • Federation of Canadian Municipalities (FCM) Sustainable Community Awards: Affordable Housing Retrofit, 2022
  • Ontario Heritage Trust: Lieutenant Governor's Award, 2022
  • The National Program of Sustainable Architecture & Building Magazine (SAB): Canadian Green Building Awards: Existing Building Upgrade Award, 2023


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