What is a passive house?

How does a passive house work?

Passive houses work by creating a comfortable interior temperature and climate that stays consistent without active heating or cooling. They do this in a few key ways, using high-quality insulation and ventilation as primary components.

Heated air inside a home often escapes through the path of least resistance, called a “thermal bridge.” Houses often lose heat through small cracks, inefficient windows, or poor insulation. A passive house seals these areas and removes the thermal bridge. Features such as super insulation and quality ventilation help prevent heat loss so homeowners can live comfortably while the house maintains its temperature. 

Passive houses also use “free heat” to warm the home. Free heat comes from things like body temperature, gas, ovens, computers, and light bulbs. This, combined with other passive ways to maintain a home’s temperature based on climate — like using shade to cool a home in a warmer climate — makes for a highly efficient indoor climate. 

Since a passive home requires an official certification, any home built to meet these criteria reaps the energy savings benefits. Features like space heating and cooling demand, energy demand, and airtightness are each measured and contribute to earning the certification. 

Key features of a passive home include:

• Super insulation: A layer of efficient insulation wraps around the entire building, including beneath the foundation and around basements, to reduce heat transfer from inside and outside.
• Quality ventilation: Ventilation systems exchange moist air that may contain allergens for fresh air from outdoors. This helps maintain the temperature and humidity inside the home.
• Free heating: Passive houses pass fresh exterior air through the ventilation system. When cold air enters the system, it is heated by warm air from the same system using free heat sources such as body temperature, gas, ovens, and computers.
• Efficient windows: Windows can often be a source of lost hot or cold air. Triple-paned windows with insulated frames prevent this.
• Airtight enclosures: Sealed construction prevents moist air from getting into the home, where it can impact air quality and even create mold.

Benefits of passive homes

Passive houses are not only great for the environment — they also benefit their occupants. From a quieter home to lower electric bills, here are some of the benefits of building or redesigning a home to be passive.

Reduced energy costs

One of the most appealing reasons to remodel or build a passive house is the lower energy costs. With the potential for a passive home to use 90% less energy than standard buildings, this also means lower energy bills. Because these homes heat and cool themselves without air conditioners or furnaces, monthly energy bills can be significantly lower. 

Increased comfort

Contrary to what many may think, comfort in passive houses actually can increase compared to standard construction. With a focus on insulation and high-performance ventilation, passive houses use energy sources inside the building, such as body heat, to maintain an even temperature throughout the space. 

Additionally, the difference between the temperature of doors or windows — which can often be cooler or warmer than the rest of the home — is consistent with the internal temperature of the rest of the home due to the quality of the insulation. 

Improved indoor air quality 

Passive houses are airtight, with a ventilation system that filters out pollen and allergens more quickly due to its efficiency. As a result, it also lets in far less dust as well, keeping the air fresh and free of pollutants and odors that may irritate those with allergies. As an added benefit, this makes for a quieter home!

To learn how it all comes together — from the components of a passive house to how each part leads to benefits in your day-to-day life — we’ve summed it up for you below.