Maybe you’ve seen the term “Passive House” while flipping through your favorite design magazine or social media app, and you’re curious to learn more.
Or, maybe you’re familiar with Passive Homes, and you’re considering building one yourself.
Regardless of your experience, this comprehensive guide will explain:
- What is a Passive House?
- The five common elements of all Passive Houses
- The two primary certifying bodies
- Five reasons to build a Passive House
- Ten steps to building a Passive House
- Why build a Passive House?
What is a Passive House?
Passive House has grown in popularity and is often seen as a catalyst in the fight against the climate crisis. It also has an interesting history.
Physicist Wolfgan Feist and structural engineer Bo Adamson created a research cooperation in 1988 centered on building a “house without heating.” Together they built the world’s first Passive House in Darnstadt-Kranichstein, Germany in 1991. The goal was to build a home with no active heating, which could be kept warm “passively,” using internal heat sources, solar energy and fresh air. The trial was successful, and they encouraged others to apply their practices and methodology.
Today, the concept of a Passive House has evolved, yet at its core, its principles of energy-efficiency and sustainability remain. While the word “house” is in its name, a Passive House can refer to any building type including apartments, schools, hospital, restaurants, offices, commercial areas and more.
5 Common Elements of Passive Homes
Regardless of the building type, all Passive House construction projects share five common elements. Let’s dive into each one.
1) Continuous Insulation
A building envelope is what separates the interior from the exterior of a building, outside walls, roofs and floors. However, when a building is heated, some heat is lost as it moves through the envelope via conduction. This occurs when insulation is made of low-conductivity materials, seen in traditional construction.
In contrast, a Passive House improves the envelope by super insulating the building to minimize heat loss. Typically, a Passive House will use enough insulation to double or triple the heat resistance compared to standard building code requirements. In addition to significantly superior thermal performance, you can also expect better soundproofing, improved durability and the ability to keep structures warm during a power failure.
2) No Thermal Bridges
Thermal bridges are weak points in a building envelope which allow heat to easily pass. You’ll see thermal bridges in walls, roofs, windows and balconies. A Passive House minimizes thermal bridges. You can eliminate thermal bridges by reducing the number of corners to promote airflow or select the right building materials like self-supported decks and canopies.
Critically, fenestration – where you place windows and doors – affects thermal bridges. Installing a window to line up with the insulation layer, leveraging the right materials and choosing the right type of windows will also minimize thermal bridges.
3) Airtight Construction
Heat is often lost through the envelope through air leakage. Gaps in a building’s air barrier (membrane, tape, seals) allows air to move in and out of a building, often uncontrolled. A Passive House eliminates this problem with a tightened envelope and mechanical ventilation.
To achieve Passive House Certification, a building needs to have less than 0.6 air changes per hour (ACH50). To achieve this, you need effective planning, high-quality materials and professional installation.
4) High-Performance Windows and Doors
Windows and doors – often referred to as a building’s glazing system – play an integral part in Passive House construction. With the functionality to open and close, you must use high-quality windows and doors to reduce heat flow.
Some qualities of high-performing windows and doors include nonconductive framing, insulated framing, double or triple glazed units, multiple Low-E coatings and warm edge or nonconductive spacers. Examples include EuroLine’s 4700 ThermoPlus® Tilt & Turn Windows and EuroLine’s Energeto Tilt & Glide Doors.
5) Fresh Air Ventilation with Heat Recovery
Because a Passive House is airtight in nature, a ventilation system is required to promote fresh airflow and the ability to remove built-up pollutants. A Passive House ventilation system uses a heat recovery ventilator (HRV) to continuously remove stale air and bring in fresh air.
The system extracts heat from exhaust air and places it in the incoming air without mixing the airstreams. This helps ensure heat in the exhaust is not eliminated and delivered outside, but instead, is reused to heat the space. A Passive House HRV requires at least 75% of heat to be recovered.
Who Sets Passive House Standards?
There are three main bodies that set Passive House Standards globally: The Passive House Institute, Phius and the International Passive House Association. Let’s take a closer look at each.
1) The Passive House Institute
The Passive House Institute is widely known as the central arbiter for Passive House Certification and has strict, quantifiable criteria that must be met. These include:
- The Space heating Energy Demand not to exceed 15kWh per square meter of net living space.
- The total energy to be used for all domestic applications (called the Renewable Primary Energy Demand) must not exceed 60 kWh per square meter of treated floor area per year.
- For Airtightness, a maximum of 0.6 air changes per hour at 50 Pascals pressure (ACH60) as verified by an onsite pressure test.
- Thermal comfort must be met for all living areas during winter and summer, with not more than 10% of the hours in a given year over 25°C.
While you can request certification for specific buildings, individuals can also become certified. For example, home designers, consultants and tradespeople can be certified through work on a Passive House or rigorous examination.
2) Phius
Another organization, Phius, also provides Passive House certification to projects, products and professionals. Like The Passive House Institute, you can:
- Submit specific projects for certification
- Get products like windows and doors certified
- Become Phius Certified Consultant (CPHC®), Phius Certified Builder (CPHB), Phius Certified Rater, or Phius Certified Verifier
3) International Passive House Association
Lastly, if you’re interested in learning about the community, there’s the International Passive House Association (iPHA). The iPHA is a global network of Passive House stakeholders including architects, planners, scientists, suppliers, manufacturers, policymakers, contractors, developers and more. Together with multiple affiliate organizations, they encourage the exchange of Passive House knowledge in policy, the media and among the public.
Why Build a Passive House?
Now that you’re up to speed on its history, the five common elements, and its governing bodies, you might be wondering why build a Passive House?
While there seems to be complexity in the design and construction process, there are numerous long-term benefits to building a Passive House. Let’s go through some of them.
1) Sustainability
First and foremost, building a Passive House is incredibly sustainable and energy efficient. For comparison, a Passive House requires as little as 10% of energy used by a typical European building which means energy savings of 90%. They produce little to no greenhouse emissions (GHE) making them a helpful tool in fighting climate change.
Using sustainable products, thoughtful design and strategic construction, Passive Houses provide a forward-thinking approach to building that’s better for the environment in the long-term.
2) Cost Savings
The upfront costs of building a Passive House are roughly 8% higher than a conventional house but offer greater long-term cost savings. Firstly, with energy costs rising, owners of Passive Houses will continue to only pay a fraction. Secondly, depending on where you live, there are various government incentives and rebate programs that further reduce building costs.
You’ll also spend less on home maintenance and upkeep. By leveraging sustainable products in the outset, and due to its robust construction, inactive components of the house will continue to perform at a high level for years to come.
3) Comfort & Air Quality
Residents of Passive Houses also mention comfort as a key benefit. A well-insulated envelope and superior glazing keeps the interior at a consistent temperature, all year round. High-quality windows and doors help to eliminate cold drafts, and little change in radiant temperature (the average temperature of surfaces).
Ventilation is also an advantage. The steady flow of fresh air will improve ventilation, eliminate odors and reduce humidity within the home.
4) Versatility
While you may think the rules to build a Passive house are quite stringent, it surprisingly offers a wealth of versatility. First, there is no specific construction method required, which means you can design your Passive House to your own preference. This includes having liberty to build using wood, composite or prefabricated materials.
To increase sustainability, you can apply Passive House principles to retrofits for various building types such as schools, hotels, office buildings and more. Depending on where in the world, the climate will also dictate what products and designs will be best suited.
5) Soundproofing
When compared to conventional homes, a Passive House provides superior soundproofing. A heavily insulated envelope and high-performance windows and doors significantly reduces outside noise.
Within the home’s interior, soundproofing between each room is also improved. In addition, advanced ventilation systems are much quieter than ones used in traditional homes.
How to Get Started in Building Your Passive House
If you’re sold on building a Passive House, there are a few crucial steps to get started. Let’s dig into each of the ten steps.
Step 1: Partner with a Passive House Consultant
Building a Passive House is very different from building a conventional home, and having a certified consultant by your side is key. The first step is finding a trusted Passive House consultant before you start planning your design.
Better yet, find a consultant who is from the area you want to build – either someone who lives there or has experience building in that location. They will have deeper knowledge into specific municipal or state regulations that you wouldn’t ordinarily know.
Step 2: Get in Touch with Governing Bodies
It’s best to involve the appropriate certifying body early in the process. Your certified consultant will help you determine which organization to reach out to. This will help to de-risk your project and inform you on what specific programs to enroll into (like WUFI or PHPP) and ultimately remove the guesswork.
Step 3: Find a Passive House Certified Tradesperson & Architect
The next step is adding the final members of your Passive House team. You’ll need to partner with a contractor or tradesperson who is also Passive House Certified.
They’ll be your go-to-person during the design and construction process. Depending on who you partner with, they may supply an architect on the project. If not, you’ll need to find an architect who is also familiar with Passive House standards.
Step 4: Document Your Strategies for Air Sealing and Ventilation
Within your construction documents, you’ll need detailed strategies for a few key areas to ensure you get Passive House Certified. First is air sealing which refers to how you plan to keep a tight building envelope through continuous insulation. This involves selecting the right products like tape, membranes and more.
Next, document your ventilation strategy which will likely include mechanical systems like a heat recovery ventilator (HRV) to continuously remove stale air and bring in fresh air. Other systems you’ll need to consider include heat pumps, ERVs, range hoods, dehumidifiers, water heaters and laundry machines.
All these need to be documented with clear diagrams and descriptions before breaking ground on a project.
Step 5: Drawing & Design
Work with your Passive House team to design your home. Often, homeowners will have an initial vision based on how they want the house to function. Use this as the basis for your architect to design the home with Passive House standards in mind.
They will have suggestions on layout and design and helpful recommendations to ensure your home will pass the rigorous certification requirements.
Step 6: Select Your Window and Doors Partner
Once the house is designed, a key step is finding the right windows and doors company who have experience with Passive House construction. It’s essential to select high-performance products that effectively let light in while reducing heat flow.
EuroLine Windows and Doors is a North American leader in high-quality windows and doors trusted by hundreds of Passive House projects. Our windows and doors are meticulously crafted for sustainable design, energy efficiency and eco-friendliness while maintaining an elegant aesthetic.
Step 7: Start Building and Meet Regularly
Start by having a kickoff meeting with your consultant, contractor, architect and any other subcontractors involved. Once a start date is established and construction begins, hold regular weekly meetings to check on the progress of the project.
This will keep all parties involved accountable helping you stay on track and on budget. It also gives contractors the chance to update you on any roadblocks, and lets you make quick decisions that don’t hinder your timeline.
Step 8: Use the Blower Door Test Regularly
As construction progresses, regularly conduct blower door tests. A blower door test is a tool that determines how much air is entering and escaping from your home. With airflow being vital for Passive House Certification, this test is crucial. Conduct multiple blower door tests during and after construction.
Blower door tests during construction helps you uncover air leaks and lets you fix it right away. Conduct the test again after windows and doors are installed, and again at the conclusion of construction.
Step 9: Commissioning
Commissioning is the process of testing all building systems and ensuring it’s performing to its design intent. During this phase, you’ll need to test all the systems within the home. This includes learning simple day-to-day things like how to change filters, programing thermostats and how to operate certain appliances.
It’s often in the commissioning phase that you’ll find things will need to be slightly adjusted or fixed.
Step 10: Submit for Certification
The last step is submitting your property for certification. Work with your consultant to ensure all documents are in place before submitting to the governing body you selected in step 2. This includes floorplans, and the appropriate photos of both the interior and exterior of the home, along with detailed descriptions for each.
Final Thoughts
While seemingly rigorous and technical, you may ask yourself, why build a passive house? For most, it’s because they want to be part of a more sustainable future. Beginning as a simple concept, the Passive House movement has grown into an internationally known approach to building. With the emergence of forward-thinking architects, developers and consumers, Passive House construction may soon become the norm.
