Do you want to live in a comfortable, eco-friendly home that drastically reduces your energy bills? Are you wondering how such a project could become a reality? Building a passive house might be the solution.
Of course, this type of project can seem complex and intimidating. But don’t worry, I’m here to guide you. As a Passive House designer and LEED Green Associate, I am currently helping clients achieve these two standards for their home extensions and renovations. The steps I present here are the ones I am going through with them. Therefore, I can guide you through them by giving you practical advice to help you achieve your dream of a passive house without stress or hassle.
1. Defining Your Energy Goals
One of the first steps in embarking on a passive house project is to clearly define your goals. This may seem obvious, but it is crucial to know exactly what performance you are aiming for before you begin. Do you want to maximize energy efficiency? Reduce your carbon footprint? Create a healthier living environment for your family? Are you aiming for certification? By clarifying these priorities from the start, you can guide all your design and construction decisions in a coherent manner.
Ask yourself simple but essential questions: What is your budget? What are your long-term sustainability goals? Do you have specific design or material requirements? By answering these questions, you can establish a clear and structured roadmap for your project.
If you aim for passive certification, understanding the criteria for this type of construction is also crucial. A passive house must maintain a comfortable indoor temperature year-round with minimal energy. This means excellent insulation, rigorous airtightness, and efficient ventilation systems.
Passive House Standards:
Heating demand: Less than 15 kWh/m²/year.
Airtightness: N50 < 0.6 air changes per hour at 50 Pascals.
Low-Energy House Standards (according to the Passivhaus Institute):
Heating demand: Less than 30 kWh/m²/year.
Airtightness: N50 < 1.0 air changes per hour at 50 Pascals.
In comparison, a standard house in Quebec consumes an average of about 22,000 kWh per year, which translates to approximately 220 kWh/m²/year for a 100 m² house, according to Statistics Canada. If we consider that 50% of this energy is dedicated to heating, we can estimate that a standard house needs about 110 kWh/m²/year for heating: 7 times more than a passive house!
(See the breakdown of household consumption on Hydro-Québec’s website.)
By understanding these criteria, you will be better prepared to make the necessary choices to achieve your goals.
2. Selecting the Project Team
To successfully complete a passive house project, it is essential to surround yourself with the right professionals. Building a passive house requires specific expertise and close collaboration between various stakeholders, from the architect to the craftsmen, engineers, and energy efficiency consultants.
Choosing the Right Professionals
Architects: Choose professionals with proven experience in designing passive houses. They will understand the specific requirements of this type of construction and help you design a house that meets your goals while respecting energy performance standards.
Energy Efficiency Consultants: These experts are essential for conducting energy simulations and optimizing your future home’s performance. A certified passive house consultant can use tools like the PHPP (Passive House Planning Package) software to ensure your house meets the required standards.
Contractors and Qualified Craftsmen: Ensure that the contractors you hire have experience with the specific construction techniques for passive houses, particularly in terms of insulation and airtightness.
Passive House Certifiers: If your goal is to achieve passive house certification, you will also need to hire a certifier. This person can act as a consultant, but their main role is to independently verify and compile the documentation for submission to the Passive House Institute for certification.
Collaborate from the Start
An integrated approach is crucial for a passive house project. From the early stages of design, all professionals involved must collaborate closely. This collaborative approach allows potential challenges to be identified and resolved before they become costly problems.
Train and Inform
It can be beneficial to train your craftsmen and workers in the specific techniques of passive houses. Short, specialized training courses are available and can significantly improve construction quality.
Resources and Networking
Use available resources such as passive house associations and professional networks to find experts and share knowledge. Participating in forums and discussion groups can provide you with valuable advice and recommendations for qualified professionals.
3. A Simple Design to Maximize Energy Efficiency
Simplicity in design and volumetry is one of the keys to success in meeting passive house standards. A simple design not only makes construction easier but also contributes to improving energy efficiency and reducing costs.
Why Prioritize Simplicity?
Reduce the Envelope-to-Area Ratio: Less surface contact between the inside and outside means fewer potential heat losses.
Reduction of Thermal Bridges: Simple, compact shapes minimize thermal bridges, where heat can escape more easily.
Optimized Insulation and Airtightness: Complex shapes make the application of insulation and airtightness more difficult and expensive.
Ease of Construction: Simple plans require fewer materials and labor, reducing the risk of errors and delays.
How to Design Simple and Efficient Plans?
Opt for compact, regular shapes like rectangles or squares.
Prefer simple roofs without multiple levels or complex slopes.
Reduce the number of corners and angles.
4. Simulations to Optimize Energy Performance
Once the preliminary concept and general volumetry are determined, we can conduct an initial energy analysis. Energy analysis is a crucial step in designing a passive house. It allows you to simulate and optimize the building’s energy performance before construction begins. One of the most commonly used tools for this analysis is the PHPP (Passive House Planning Package) software.
What is PHPP?
PHPP is an energy calculation and planning tool specifically designed for passive buildings. It allows you to model the energy performance of a building by considering various factors such as insulation, airtightness, solar gains, and mechanical systems. This tool helps designers ensure that the building meets the strict criteria of passive houses.
Performance Optimization: PHPP helps identify the project's weak points and test different solutions to optimize energy performance. This may include adjustments to insulation, airtightness, building orientation, and the choice of mechanical systems.
Compliance Verification: Once optimizations are made, PHPP checks whether the project meets passive house criteria. These criteria include primary energy consumption below 120 kWh/m²/year, heating demand below 15 kWh/m²/year, and airtightness with N50 < 0.6 air changes per hour at 50 Pascals.
5. Technical Design by Professionals
At this stage, the architect and contractor will discuss the construction strategies considered to achieve the desired level of insulation for each component of the house, including floors, exterior walls, and the roof. They will also focus on junction details to avoid thermal bridges. These discussions are essential to ensure optimal thermal performance and meet passive house standards.
6. Choosing Mechanical Systems (the Heart and Lungs of the House)
The shape of the house is important for meeting passive standards, as is the technical composition of the walls, floors, and roof. However, the choice of mechanical systems is equally important. Mechanical systems play a crucial role in the energy performance and comfort of a passive house. They include heating, ventilation, and air conditioning (HVAC) systems. In a passive house, these systems must be carefully planned and integrated to ensure maximum efficiency. It is essential to be well informed about the various options available and to receive sound advice on choosing and sizing the most suitable system for your specific project.
Heating and Cooling
Air-to-Air and Air-to-Water Heat Pumps: These systems are highly efficient as they use a small amount of electricity to transfer heat from the outside air to the inside of the house (or vice versa in cooling mode), even at very low temperatures. This allows you to maintain a comfortable indoor temperature year-round with minimal energy consumption.
Ventilation
Mechanical Ventilation with Heat Recovery (MVHR): A mechanical ventilation system with heat recovery is essential in a passive house. Since passive houses are extremely airtight, an efficient air exchanger is needed to ensure a continuous supply of fresh air in all rooms of the house. It recovers the heat from the outgoing air to preheat the incoming air, thus reducing heating needs. For projects aiming for passive certification, it is recommended to choose units certified by the Passive House Institute to guarantee optimal performance.
From Idea to Action: Summary of Key Steps
Embarking on a passive house project is an ambitious but highly rewarding endeavor. By following the key steps we have discussed, you will be able to create a comfortable, sustainable, and energy-efficient living environment. Here is a summary of the essential steps to ensure the success of your project:
Define your energy and environmental goals: Clarify your priorities and objectives in terms of energy performance, carbon footprint reduction, and creating a healthy living environment.
Select and collaborate with the right professionals: Surround yourself with experienced professionals in passive house construction to ensure the success of your project.
Simplify the design to maximize energy efficiency: Opt for simple plans and compact shapes to minimize heat loss and optimize energy efficiency.
Use PHPP to optimize energy performance: Conduct energy simulations with the PHPP software to optimize your home's energy performance before construction.
Avoid thermal bridges for optimal insulation: Work with your architect and contractor to develop construction strategies and avoid thermal bridges.
Choose efficient HVAC systems for a passive house: Carefully select heating, ventilation, and air conditioning systems suited to the reduced energy needs of your passive house.
Each step is crucial to ensure that your passive house meets strict energy performance criteria while offering optimal comfort. Being well-informed and guided throughout the process will help you avoid costly mistakes and ensure the success of your project.
Building a passive house is not just about complying with standards; it’s also about creating a healthy, comfortable, and environmentally friendly living space. With careful planning and the right strategies, you can achieve these goals and enjoy the many benefits that a passive house offers.
Next Steps:
Ask your questions and get personalized advice: If you have any questions or need more information about any of the steps, don't hesitate to contact me. I’m here to help you throughout your passive house project.
Read our detailed article on passive houses: To deepen your knowledge and learn more about passive houses, check out our complete article on passive houses here.
In summary, every passive house project is unique. Your personal goals and the specific conditions of your site will play a crucial role in defining your approach. Take the time to think about what you truly want and make sure that each decision you make brings you closer to your goals. By adopting a thoughtful and well-informed approach, you can turn your dream of a passive house into reality.
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