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Ken Soble Tower
Background
Ken Soble Tower is a 1960s, 146‑unit seniors’ building owned by CityHousing Hamilton, a municipally- owned housing provider with approximately 7,000 units and 13,000 residents. After decades of underinvestment and significant deferred maintenance across their housing portfolio, this tower had been partially vacated and was considered by the organisation as a candidate for demolition. Instead, CityHousing Hamilton, used it as a testbed for a new development and retrofit strategy that treats affordable housing as critical climate infrastructure. The project pursued a deep energy retrofit to EnerPHit / Passive House standards, demonstrating how aging post-war housing towers can be renewed to achieve very low energy use, improved comfort, and major emissions reductions.
Location:
Hamilton, Ontario, Canada
Typology:
Deep Energy Retrofit of Social Housing Tower
Time frame:
Retrofit completed in 2021
Emissions Reduction and Efficiency Strategy
The Ken Soble retrofit combined comprehensive envelope upgrades, higher performing systems, and a whole‑building design approach to dramatically reduce energy demand. The recladding and insulation strategy, using air‑sealing, and triple‑glazed windows, reduced space‑heating loads to the point that the building no longer required connection to the adjacent district energy system, despite Hamilton’s cold climate. High‑efficiency mechanical ventilation with heat recovery, electrified heating and hot water, and careful detailing around thermal bridges contributed to an overall 94% reduction in operational greenhouse gas emissions compared to the pre‑retrofit baseline.
Notably, the project approached energy performance and resident health as mutually beneficial goals. Indoor air quality and thermal comfort were substantially improved, with the retrofitted tower now performing better than a typical single‑family home in terms of energy use intensity, while providing residents with quieter, more comfortable, and healthier living spaces. The retrofit also improved accessibility and communal living through a renewed entrance, community room, accessible terrace, community garden, communal laundry, rooftop community room and a mix of units, including barrier-free units. For CityHousing Hamilton, the building serves as a proof of concept that the retrofit of existing housing stock can extend asset life and reduce long‑term operating costs, while also aligning social housing with municipal and federal climate targets.
Delivery Mechanisms
CityHousing Hamilton delivered Ken Soble within a broader organisational shift away from individual project partnerships and land divestments and owards in‑house development and long‑term stewardship of its municipal housing assets. The tower retrofit reperesented a $39.8 million investment within CityHousing Hamilton’s broader $221.8 million development programme, financed through an approximate mix of 40% grants, 30% loans, and 30% equity. Rents were set at 55% of average market rent, situating the project within CityHousing Hamilton’s broader affordability range of roughly 45–67% of an adjustable mortgage rate.
The retrofit has stood as part of a larger series of high‑performance projects, including Passive House new builds and mass timber developments, allowing the organisation to build internal expertise in low‑energy design and construction. Lessons from Ken Soble Tower have informed specification standards, procurement approaches, and asset management practices across the wider portfolio, positioning efficiency and emissions reduction as core business rather than niche innovation.
Implementation Challenges
Delivering such a significant retrofit on an aging social housing tower required navigating technical, financial, and regulatory challenges, including the broader issue of adapting deep retrofit methods to buildings that may be occupied, partially occupied and/or in poor condition. CityHousing Hamilton staff highlighted the challenge of reconciling their targets for high building performance with tight public‑sector budgets and an already strained capital programme. As with other projects in the development pipeline, regulatory approvals and coordination with utilities and contractors have the potential to introduce delays, while the city’s broader housing stock’s substantial maintenance backlog limited how quickly similar interventions could be replicated in other buildings. Post-retrofit, challenges have emerged around resident comfort, such as overheating in the summer months – a common passive house challenge which requires that air temperature, radiant temperature, ventilation, shading, and cooling are carefully balanced.
More broadly, the Ken Soble Tower retrofit underscored the challenge of scaling-up a single project into a systematic response to climate and housing pressures. While Ken Soble Tower sets a benchmark, given resource constraints, CityHousing Hamilton must weigh up the pursuit of EnerPHit‑level performance against pragmatic choices that result in more modest or phased upgrades.
Lessons learned
Framing affordable housing as climate infrastructure
This can help justify major capital investment and supports alignment with emissions targets.
Limits to knowledge transfer and scaling
Flagship projects like Ken Soble Tower can build organisational knowledge and external credibility, but replicating this model across large, aging portfolios depends on dedicated funding, the specialised skills of municipal staff and local consultants, as well as realistic phasing.
Public ownership
Public ownership and internal development capacity gives municipalities greater control over performance standards, tenancy, and long‑term affordability.
Although Ken Soble Tower is often discussed as an energy retrofit and therefore a case study on emissions, the project is also part of a broader tower renewal approach that links decarbonisation with housing quality, resilience, accessibility, and sustainable development.