All you need to know about Passivhaus
Passivhaus, also known as Passive House, is a rigorous and voluntary energy efficiency standard for buildings. It was developed in Germany in the late 20th century and has since gained popularity worldwide. The primary goal of Passivhaus is to create buildings that are highly energy-efficient, comfortable, and have minimal environmental impact.
The Passivhaus standard is based on specific criteria for energy performance. For example, the annual heating and cooling energy usage must be below a certain threshold (typically 15 kWh/m² per year), and the overall primary energy consumption must also meet stringent requirements.
The Passivhaus standard is applied to a variety of building types, from single-family homes to multi-family buildings and commercial structures. Certification from the Passivhaus Institute is available to ensure that a building meets the required standards.
What are the key characteristics of Passivhaus?
Superb Insulation. Passivhaus buildings are extremely well-insulated to minimise heat loss, with insulation levels significantly higher than in conventional buildings.
Airtight Construction. These buildings are constructed to be extremely airtight, preventing uncontrolled air leakage, which can cause heat loss and reduce energy efficiency.
High-Performance Windows and Doors. Passivhaus buildings use advanced, triple-glazed windows and well-insulated doors to reduce heat transfer and improve comfort.
Heat Recovery Ventilation. A mechanical ventilation system with heat recovery is essential. It brings in fresh air while extracting heat from the outgoing stale air, ensuring good indoor air quality and energy efficiency.
Minimal Thermal Bridges. Passivhaus designs pay careful attention to reducing thermal bridges, which are pathways for heat to escape through the building's structure.
Energy-Efficient Appliances and Lighting. Energy-efficient appliances and lighting are typically used to reduce the building's overall energy consumption.
Renewable Energy Integration. While not a strict requirement, many Passivhaus buildings incorporate renewable energy sources, like solar panels, to further reduce their environmental impact.
What are the requirements for Passivhaus?
For a building to be considered a Passive House, it must meet the following criteria:
1. The Space Heating Energy Demand must not exceed 15 kWh per square meter of net living space (treated floor area) per year or 10 W per square meter peak demand. In climates where active cooling is needed, the Space Cooling Energy Demand requirement roughly matches the heat demand requirements above, with an additional allowance for dehumidification.
2. The Renewable Primary Energy Demand, the total energy to be used for all domestic applications (heating, hot water and domestic electricity) must not exceed 60 kWh per square meter of treated floor area per year for Passive House Classic.
3. In terms of Airtightness, a maximum of 0.6 air changes per hour at 50 Pascals pressure (ACH50), as verified with an onsite pressure test (in both pressurised and depressurised states).
4. Thermal comfort must be met for all living areas during winter as well as in summer, with no more than 10 % of the hours in a given year over 25 °C.
What are some benefits of Passivhaus?
Passivhaus buildings offer a wide range of benefits, which is why they have gained popularity in the construction industry. Here are some of the key advantages of Passivhaus buildings:
Passivhaus buildings are extremely energy-efficient and can achieve heating and cooling energy savings of up to 80% compared to conventional buildings. This leads to significantly reduced energy bills for occupants.
Passivhaus buildings have a lower carbon footprint due to their reduced energy consumption. They contribute to mitigating climate change by lowering greenhouse gas emissions associated with heating and cooling.
These buildings are designed to provide a high level of thermal comfort. They maintain stable and uniform temperatures throughout the year, with minimal temperature fluctuations and cold drafts, enhancing occupant well-being.
Passivhaus certification can increase the resale value of a property, as it indicates a high level of energy efficiency and comfort.
The attention to detail in Passivhaus construction, such as minimising thermal bridges and using high-quality materials, often results in increased building durability and a longer lifespan.
In many countries, there are incentives, tax breaks, and subsidies available for Passivhaus construction, making it an attractive option for homeowners and developers.
While the Passivhaus standard originated in Germany, it can be adapted to various climates and regions, making it a versatile approach to sustainable building.
It's important to note that achieving the Passivhaus standard may require careful planning, precise construction techniques, and a somewhat higher upfront investment. However, the long-term benefits, both in terms of cost savings and environmental impact, make it a compelling option for those looking to build or renovate energy-efficient and sustainable buildings. If you would like to know more about how you can incorporate this into your project call our team today. They would love to discuss this with you!