Passive House represents the pinnacle of energy efficiency in architectural design, demanding minimal energy for heating or cooling purposes. The primary goal of a Passive House is to create an environmentally friendly and comfortable living space by minimizing energy consumption and controlling the indoor environment through specific design principles and construction methodologies. A Passive House is also quiet, durable, healthy and resilient.
Passive House design aims to foster an environmentally-friendly living area by maximizing energy efficiency. This objective is fulfilled by implementing a specific set of principles and construction techniques.
Passive House Standards refer to the criteria that buildings must meet to earn the ‘Passive House’ label. These criteria include heating and cooling demand, and air tightness. The design and construction of these energy-efficient buildings are guided by five principles: super-insulation, an airtight building envelope, high-performance glazing, thermal-bridge-free detailing, and heat recovery ventilation.
Refurbishing an existing home to meet Passive House standards involves updating mechanical systems, windows and doors, insulation, and the air barrier to improve energy performance. These upgrades, when taken together and properly executed, can elevate even an older home to a level of energy efficiency that greatly surpasses current building standards.
Super-insulated envelopes are essential for achieving the high levels of energy efficiency required for Passive House buildings. The walls, roof, and floor of a Passive House building must be very well insulated to prevent heat from moving in and out of the house through conduction. Super-insulation is achieved by proper installation of high-performance insulation materials, such as blown-in cellulose or mineral wool.
Airtight construction is another key component of Passive House design. An airtight building envelope helps to prevent hot or cold air from moving in and out of the house. This can be achieved by installing an airtight membrane around the home and sealing all cracks and gaps in the walls, roof, and floor.
High-performance glazing is also important for Passive House buildings. The windows of a Passive House building must be very energy efficient in order to prevent heat from entering or leaving the house. This can be achieved by using triple-pane windows with a high R-value.
Thermal-bridge-free detailing is another key consideration for Passive House buildings. Thermal bridges are areas where heat can easily move in or out of a building through solid materials. These can be caused by uninsulated metal studs or other materials that have a high thermal conductivity. In Passive House buildings, thermal bridges are carefully avoided or minimized.
Heat recovery ventilation is a system that provides continuous fresh air to a building while also recovering the heat in the outgoing air. This is an important part of Passive House design, as it helps to maintain indoor air quality while reducing energy consumption.
These are just some of the techniques and materials that are used to retrofit existing buildings to Passive House standards. By following these principles, it is possible to transform an existing home into a highly energy-efficient and comfortable living space.
Another upgrade approach for homeowners to consider is EnerPHit, a more achievable standard of Passive House design tailored for existing building retrofits. It incorporates a set of standards including the use of thermal insulation, high-quality windows, and ventilation with extremely efficient heat recovery, leading to significant energy savings.
Retrofitting an existing home to Passive House standards can present several challenges and considerations.
A prime challenge of retrofitting projects lies in dealing with existing conditions. Age, location, and structure type might impose limits on access, space, or resources to execute the retrofitting work. Ensuring structural compatibility and integrity between existing and new components presents another hurdle.
Benefits of retrofitting include significant energy savings (up to 70% in some cases), resulting in lower energy bills and reduced greenhouse gas emissions. Passive House buildings offer superior comfort, remaining warm in winter and cool in summer without the need for traditional HVAC systems. They also provide better indoor air quality due to their airtight construction and ventilation systems equipped with heat recovery, creating a healthier living environment. Moreover, due to their energy efficiency and environmental benefits, Passive House buildings can have a higher market value.
Retrofitting an existing home or building a new one are both viable options for achieving energy efficiency and reducing negative environmental impacts. However, there are some key differences between the two approaches that should be considered.
In terms of cost, retrofitting is typically less expensive than new construction. However, the cost of retrofitting can vary depending on the size and condition of the building, as well as the materials and labor costs in the area. Also, the return on investment of a retrofit might be less than that of a new build.
In terms of energy savings, both retrofitting and new construction can result in an extremely energy-efficient home. However, retrofitting an existing building may not achieve the same level of energy savings as building a new Passive House from the ground up due to constraints imposed by the existing structure.
In terms of environmental impact, both retrofitting and new construction can have a positive impact by reducing the greenhouse gas emissions generated by operating the home, though the impact might be greater in a new Passive House. However, building a new Passive House from the ground up may have a lower environmental impact than retrofitting an existing building, as it can use more sustainable materials and construction methods.
Ultimately, the best option for you will depend on your individual needs and preferences.
If you are looking for a more cost-effective option, retrofitting may be the best choice for you. However, if you are looking for the highest level of energy efficiency and environmental impact, building a new Passive House may be preferable.
Making your home a Passive House can be a path toward energy efficiency, environmental responsibility, and enhanced comfort. Both retrofitting an existing house and building a new Passive House have their unique benefits and challenges. Whether you’re intrigued by the prospect of living in a Passive House or still weighing the options, we invite you to reach out to Carmel Building & Design.
Our team of Passive House experts will be more than happy to guide you through the process and answer any questions you may have. Together, we can explore how we can tailor your home to the Passive House standards, aligning with your needs, preferences, and budget. Contact us today to schedule a consultation, and let’s embark on this journey toward a sustainable and energy-efficient future.
March 1, 2023 Blog
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