We call the project Net Zero with the understanding that the term refers to a goal that is difficult to attain, particularly on a renovation project. To approach the goal, we focused on reducing the energy use side of the equation by adhering to Passive House standards as much as possible.
The systems that were developed included a super insulated envelope, air-tight construction, elimination of thermal bridging, high-tech windows and doors, passive solar heating and shading, and an energy recovery ventilation system with a goal of reducing the energy demand by 80%. We established a base line with a blower door test on the existing house, during construction and one soon to come.