During the session, Catherine also introduced EnerPHit, the Passive House approach to retrofitting existing buildings. While it shares many of the same principles as new-build Passive House projects, its requirements are slightly more flexible, acknowledging the challenges of upgrading older structures. Despite this, retrofitted buildings still achieve an estimated 80% reduction in heating demand compared to non-retrofitted homes, demonstrating its effectiveness in improving energy efficiency.
Catherine addressed common myths surrounding Passive House design, clarifying misconceptions that can sometimes deter adoption. One widely held belief is that Passive House buildings do not allow windows to be opened. In reality, while Mechanical Ventilation with Heat Recovery (MVHR) units continuously circulate and filter air, occupants can still open windows whenever they choose. Another misconception is that Passive House buildings are prone to overheating due to added insulation. Catherine explained that effective glazing, building orientation, and shading strategies prevent this issue. Similarly, concerns about stuffiness are unfounded, as MVHR units provide a constant supply of fresh air, improving indoor air quality. She also highlighted that Passive House design is not limited to residential buildings but is successfully applied to schools, offices, and other building types.
While there are some additional upfront costs associated with Passive House construction—typically 3-8% higher than conventional builds—these are balanced by long-term savings on energy and maintenance. The benefits of Passive House design extend beyond individual projects, aligning with the industry's net-zero carbon targets by significantly reducing energy demand.
