5 Building Materials to Avoid for Passive Houses

There are many facets involved in building a passive house and getting energy consumption down to zero. Obviously, installing solar panels to create renewable energy is a great place to start. It is also important to consider the orientation of your home during construction so that you can use natural sunlight for lighting and heating as much as possible. Additionally, choosing Energy Star appliances and low-flow water fixtures are other common sense measures.

However, one of the more underrated ways to ensure a passive house is to avoid materials that readily lose their insulation and require significant energy resources to maintain. With this in mind, keep reading to discover 5 types of building materials to avoid for passive houses. 

1. Windows Readily Damaged By Weather and UV Exposure

Old and degraded windows are highly susceptible to unwanted air transfer. Whether it be cracks in the window sash or a frame-to-wall transition that is no longer well-sealed, air will find the path of least resistance from the home’s conditioned interior to the outside.

As a result, it is a good idea to avoid window types known to degrade in the face of inclement weather and UV exposure. Some windows have a tendency to become brittle when confronted with weather fluctuations, which can lead to paths for unwanted air transfer. Other types of windows must be regularly treated to remain water resistant, with such active attention to detail requiring more resource consumption than is desirable for a passive house. 

For a truly passive construction, look at metal storm windows for historic homes that stand up in the face of heavy winds and require little attention to maintenance and upkeep. Even if you don’t live in an area at risk of severe weather, rugged steel windows will last the lifetime of the building without ever degrading, keeping the home as airtight and energy efficient as possible. 

2. Highly Absorptive Framing Panels

Many contractors choose to go with the most affordable framing solution. However, cutting costs during construction will inevitably show up down the road–especially when building a passive house. Many low-cost framing materials absorb water, resulting in shrinking and swelling that can cause cracking and other imperfections that will negatively impact the building envelope.

As a result, it is worthwhile to pay a little more for framing and choose inorganic options that will provide an impervious structure for the home. By going this route, builders can ensure that the home is completely resistant to mold, rot, insects, and fire, guaranteeing that the frame remains uncompromised no matter what the forces of nature bring. 

3. Low Cost Roofing Shingles

Many varieties of asphalt shingles and wooden shakes are popular roofing products thanks to their affordability and aesthetics that are compatible with a wide range of housing types. While they are solid roofing options when new, they are not great for passive house construction because they readily break down in the face of consistent UV exposure and are known to raise when confronted with heavy winds.

To guarantee a more passive roof, it may be worthwhile to look at composite roofing tiles made from a blend of rubber, fiberglass, and recycled paper products. These innovative tiles carry the highest impact and fire resistance on the market while mimicking the appearance of regular asphalt and wood products. The result is a roof that will last at least 50 years, eliminating the risk of moisture leaking or air transfer through the roof. This roofing type works is also a great choice for homes looking to install solar panels.

4. Brittle Siding Materials

Many types of mass produced siding are marketed as elite options because they do not absorb water and do not need to be painted or sealed. While this is true, those that are fabricated from lower quality plastics will become brittle when exposed to extreme temperature fluctuations, sometimes losing their effectiveness in as little as 15 years. Therefore, when choosing siding options, be sure to do your homework and find the material that will provide the best combination of low maintenance and durability to help secure the airtightness and insulation of your passive home for as long as possible. 

5. Old Fashioned Soffit

Like other recommendations listed throughout this article, many traditional soffit products look good when new but must be regularly tended to in order to continue functioning properly. Specifically, soffit can absorb moisture runoff from the roof, resulting in poor ventilation in the roof and attic that can cause mold to spread like wildfire. 

As such, modern soffit is made out of durable, inorganic materials with ventilation holes added in to promote airflow. This prevents moisture absorption and improves the quality of air in your attic and the buildup of mold and mildew spore. 

Achieve a Passive House By Avoiding These Common Materials

When building a passive house, it is critical that you don’t forget about energy transfer as materials lose their insulation and energy consumed to maintain and repair degraded materials. To this effect, easily damaged windows, absorptive framing panels, low cost roofing shingles, brittle siding, and old fashioned soffit are 5 types of materials to avoid when building a passive house.