Questions about energy ratings
What Building Energy Rating would a Passive House typically achieve?
This varies from project to project, although surprisingly, a Passive House may not achieve an A1 or even A2 rating. This is because achieving these ratings requires the use of renewable energy technologies for the generation of electrical energy by photo-voltaic panels or hot water by thermal solar panels. These are not necessary for a Classic Passive House Standard to be achieved although they are often introduced to reduce overall energy consumption. A Passive House is superb for reducing energy heating costs, whilst the use of renewable energy sources is required for an A rating.
Is a Passive House also a Net Zero Carbon House?
No. You still need a minimal amount of external energy to provide a comfortable and healthy indoor climate in a Passive House, although in some regions of Europe that amount would be next to zero. The Classic Passive House standard focuses on the building envelope energy efficiency only. Once this is achieved you can turn this into a net zero energy house by adding renewables. The Passive House Plus and Passive House premium standards recognise the importance renewable energy has in reducing energy consumption.
Do I need thermal mass?
No. Thermal mass helps in the retention of solar energy. Nice to have, but not necessary as the temperature of a Passive House remains reasonably constant.