The Passive House we have been working on for the past 18 months has now become officially Certified as a Passive House and has an Energy Performance rating of A, scoring 96. But what does this mean?
To be certified as a passive house you have to hit certain criteria, for Heating, Cooling, Airtightness, and Renewable Primary Energy (PER).
The cooling system passed, being 10x better than the criteria set at 10%, recording at 1% for frequency of overheating (>25°C). For airtightness, a pressurisation test was carried out, having to pass on three separate occasions with a score of 0.6 or lower. Our house passed with an average score of 0.3.
There are no traditional heating or cooling systems used, and instead MVHR (mechanical ventilation with heat recovery) heating is used. This provides fresh filtered air into the building whilst retaining most of the energy that has already been used in heating the building.
MVHR works simply by extracting the air from the polluted sources, such as the kitchen, bathrooms, and utility rooms, and supplying air to the living rooms, such as bedrooms and lounge areas. The extracted air is taken through a central heat exchanger and the heat recovered into the supply air, ready to be circulated. This works both ways, if the air temperature inside the building is colder than the outside air temperature then the coolth is maintained in the building.
Passive House buildings offer excellent thermal comfort and very good air quality all year round. Due to their high energy efficiency, energy cost as well as green house gas emissions are extremely low.
There were also lots of other additional features added to the home to make it to the highest standard in energy efficiency. This included, A-rated triple glazed windows, Air Source Heat Pump, and solar panels with battery storage.
Checkout the progression of the build HERE.