Ken Soble Tower Passive House Retrofit

The Ken Soble Tower Transformation is a ground-breaking project to modernize a postwar apartment tower to the EnerPHit standard—one of the first such retrofits in North America. The building’s rehabilitation will modernize 146 units of affordable senior housing, while reinvigorating community spaces and outdoor gathering areas, planning for aging-in-place and barrier-free living, and providing high-quality, safe, and healthy housing for another generation. With Hamilton’s wait list for affordable housing of over 6,000 households, it was urgent that this housing asset be brought back online.

Built in 1967, the Ken Soble Tower is the oldest high-rise multiresidential building in CityHousing Hamilton’s portfolio and has been in decline for several years. After a study of several options, including sale, rebuild, capital repair, and rehabilitation, CityHousing opted to retrofit the building, making significant improvements at a cost substantially less than that of a new build. Following its modernization, the Ken Soble Tower will be a model for housing quality and energy performance for thousands of similar postwar apartment towers across the country.

At 18 storeys and more than 7,400 square metres, the Ken Soble Tower will be one of the largest EnerPHit projects in the world. The retrofit is designed for a changing climate, using 2050 temperature projections to test thermal comfort in all seasons. The project, slated for completion in 2020, will provide residents with improved comfort and control of their indoor environment, with the ability to withstand extreme climate events. Modelling has demonstrated a projected reduction of greenhouse gas emissions by 94%.



CityHousing Hamilton


ERA Architects Inc.

Mechanical Engineer

Reinbold Engineering Group

Building Envelope Engineer

Entuitive Corporation

Passive House Consultant

JMV Consulting

20190214  Community 01

The design tackled several challenging technical issues common to residential apartment towers, including the modernization of ineffective ventilation systems; replacement of aging mechanical, plumbing, and electrical distribution systems; and elimination of thermal bridging at balconies. An R-38 overcladding assembly was added to the existing masonry façade, using mineral wool insulation to minimize the carbon footprint of the airtight envelope. Innovative approaches to vertical services were used to minimize stack effect and mitigate thermal bridging through sanitary stacks, garbage chutes, and roof drains. All interior finishes were selected to ensure healthy indoor air quality, and all planting at the green roofs and ground plane was selected to be native to the Hamilton region.

The Ken Soble Tower will be 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 thousands of Canadians.


Heating demand

19.5 kWh/m²a

Cooling and dehumidification demand

2.4 kWh/m²a

Primary energy

117 kWh/m²a

Air leakage

0.6 ACH₅₀ (design)