Rehabilitating with a combination of air-to-water heat pumps, a passive solar wall, and 375 photovoltaic panels with storage can achieve a 30% reduction in the energy bill. A hybrid ventilation system and optimised envelope enable a final consumption of just 120 kWh/m²/year.
Based in Lemay’s Montreal headquarters, the 'Phenix' project is a remarkable example of how industrial building rehabilitation can become a platform for energy innovation. Rather than building from scratch, the team chose to transform a disused 1950s warehouse into a highly efficient office space, achieving a 65% reduction in carbon emissions through structural reuse. The building now consumes just 120 kWhfe/m² per year, significantly lower than the initial 350 kWhpe/m², thanks to an improved envelope, advanced HVAC systems, and a mixed-mode ventilation strategy.
At the core of its energy system are air-to-water heat pumps, supported by a passive solar wall on the south façade. This wall preheats incoming air before it reaches the pumps, stabilising performance even under extreme conditions. In parallel, the roof hosts 375 photovoltaic panels, which not only supply energy for self-consumption but also reduce peak power demand through an integrated storage system. Additionally, a dual-flow ventilation system with over 80% energy recovery, combined with natural ventilation options in spring and autumn, reinforces the building’s low-consumption approach.
Although the envelope is not fully insulated, it is compensated by triple-glazed windows on the north façade, double glazing on the south, and a roof insulated with polystyrene. This combination of technologies turns the Phenix into a living laboratory of energy efficiency, recognised with certifications such as LEED Platinum, Fitwel 3-star, and Zero Carbon Performance.
