Building a Passive House relies on simple and tested design methods and energy modeling. An experienced Passive House designer can easily design a new structure or retrofit an existing structure to the Passive House standard.
The small initial investment in an improved building envelope results in numerous benefits for developers and occupants alike. Energy cost savings, improved air quality, improved sound dampening.
As architects we use the Passive House Planning Package (PHPP) to help us when designing Passive House buildings. The PHPP is a tool developed by the PassivHaus Institute and it allows us to accurately predict the amount of energy that a building will need to consume to keep it comfortable once it is built.
As part of the Passive House design process we use thermal bridge modeling to measure the heat resistance of building components allowing us to identify potential thermal bridges at the design stage. By accurately modeling the envelope in this way we can confidently avoid thermal weaknesses in the building envelope from the beginning.
One of the primary steps in designing a building to meet the Passive House standard is to super insulated the building envelope. This is a simple and cost effective way to prevent heat loss, saving you on future energy costs, and decreasing your carbon footprint. It is important to make sure that this insulation is continuous and that there are no thermal breaks where heat can escape. Depending on the type of building, only a small amount of additional insulation can bring your home or instituation toward Passive House performance.
Thermally speaking, windows are typically very weak points in the thermal envelope, both the frame and the glazing unit itself often conduct large amounts of heat. When trying to save energy, it’s important that you reduce heat loss as much as possible in every component. To achieve the thermal resistance (U-Value) Passive House windows are typically triple glazed and filled with inert gas such as Argon which transmits less heat than air.
Most buildings loose 40% of their heat because of air loss. A Passive House avoids this by creating a very air-tight envelope. We detail our Passive House buildings to ensure that this air barrier is continuous and even when made of different materials, it is sealed tight – eliminating drafts and unwanted gaps in the envelope.
Ventilation can be a huge source of heat loss in a traditional building. In a Passive House the intake and exhaust of ventilation air is planned at an early stage and have heat recovery ventilation installed. These are devices which have an intake duct and an exhaust duct. Since the air outside the building is typically colder than the air inside (particularly at night), the heat recovery device extracts the heat from the outgoing air and transfers it to the air coming in. Some of these can recover up to 95% of the heat from the air, meaning that fresh air can continually be supplied without the associated heat loss.
Once completed, Passive House building must meet clearly defined energy, airtightness and heating targets, before they are certified. This means that the performance goals are clearly laid out from the start. The design and PHPP model is then scrutinized by an independent third party. In addition to this, site inspections form part of the certification process ensuring that the building is constructed to the standard that it was designed.