The Importance of Airtightness in Canadian Houses

The Importance of Airtightness in New Construction for Houses Built in Canada

When building houses in Canada, airtightness is one of the most critical factors in ensuring energy efficiency, comfort, and long-term durability. It doesn’t matter if you live in milder climates like Vancouver or Southern Ontario, or the colder metropolitan areas like Ottawa, Montreal, or Edmonton, the weather and climate in Canada vary wildly. Ranging from frigid winters to hot, humid summers, achieving proper air sealing in new homes has just recently become an essential part of construction. Airtightness is not only about keeping the cold air out in winter or the hot air out in summer; it’s about creating a healthier, more sustainable living environment for the long run, and will also help reduce your monthly energy bills.

What is Airtightness?

Airtightness refers to the level of seal around a building that prevents unintentional airflow between the inside and outside of the home. This includes both the “envelope” of the home (the walls, roof, foundation, and windows/doors) as well as the joints and connections between various components. Proper airtightness prevents drafts and uncontrolled air leaks, which can lead to energy loss, discomfort, and even structural damage.

Why is Airtightness Crucial for Canadian Homes?

• Energy Efficiency & Cost Savings

Maintaining a comfortable indoor temperature requires a significant amount of energy, regardless of the season or temperature outside. Proper air sealing reduces heat loss in the winter and prevents cool air from escaping during summer. According to Natural Resources Canada, homes that are poorly sealed can lose up to 25-30% of their heating energy through air leaks.

By improving the airtightness of a home, homeowners can drastically reduce their heating and cooling costs. This not only saves money on energy bills but also reduces the carbon footprint of the home, making it a more environmentally friendly living space.

• Enhanced Comfort

Air leaks can cause drafts that make certain areas of the house uncomfortable to live in. Rooms near windows, doors, and attics can feel cold during winter or hot during the summer, leading to an uneven indoor temperature. When airtightness is optimized, the home’s temperature remains consistent, creating a more comfortable living space for residents throughout the year.

• Improved Indoor Air Quality

Air leaks in homes can also bring in dust, pollen, and pollutants from the outside, which can affect the indoor air quality. This is especially important for individuals with respiratory conditions like asthma or allergies. A tightly sealed home reduces the infiltration of these unwanted particles, contributing to better indoor air quality and a healthier living environment.

• Moisture Control & Prevention of Mold Growth

In the cold Canadian climate, moisture control is a significant concern. Warm air inside a home can escape and come into contact with cold surfaces, leading to condensation. This can create the perfect breeding ground for mould, especially in basements, attics, and crawl spaces. By ensuring that air leaks are sealed properly, moisture issues can be significantly reduced, helping prevent mould growth and preserving the integrity of the building materials.

• Improved Durability and Longevity of the Home

Air leaks not only contribute to energy inefficiency and discomfort, but they can also accelerate wear and tear on building materials. Consistent exposure to moisture, temperature fluctuations, and drafts can deteriorate wood framing, insulation, and other building components over time. A properly sealed home is less likely to suffer from these types of damage, which means fewer costly repairs and a longer-lasting structure.

• Meeting Modern Building Codes

In recent years, Canadian building codes have evolved to include more stringent requirements around airtightness in new homes. The National Building Code of Canada (NBC) and local codes now focus on improving energy performance, which includes airtightness. Meeting these standards is not only beneficial for homeowners in terms of energy efficiency and comfort, but it is also a legal requirement in many areas.

For example, the EnerGuide rating system in Canada uses airtightness as one of its key measures for determining a home’s energy efficiency. Homes that meet high airtightness standards are often eligible for government incentives or rebates, which can make them more financially attractive to prospective buyers.

How to Achieve Optimal Airtightness

Achieving high airtightness in a new home requires careful planning and attention to detail during construction. Some of the strategies used to improve airtightness include:

• Sealing Gaps and Cracks: Common sources of air leaks include gaps around windows, doors, electrical outlets, and plumbing penetrations. Caulking, foam sealants, and weather-stripping can be used to seal these areas effectively.
• Quality Insulation: Insulation and air sealing go hand in hand. Proper insulation helps maintain temperature regulation, and air sealing ensures that the insulation works efficiently by preventing air from bypassing it.
• Vapor Barriers and House Wraps: Installing vapour barriers on the interior of the walls and house wraps on the exterior can prevent moisture from entering the walls while allowing for proper ventilation.
• Attention to the Building Envelope: During construction, special care must be taken to ensure that the building envelope (walls, roof, foundation, windows, and doors) is properly sealed and that there are no unintended gaps.
• Blower Door Testing: One way to measure a home’s air tightness is through a blower door test. This involves using a powerful fan to depressurize the house, allowing contractors to identify any air leaks and ensure they are properly sealed.
• AeroBarrier: AeroBarrier is the primary sealing product of Airtight Home Technologies. We have sealed over 1,000 houses, with 99.9% of those houses air leakage being reduced by 50% or better. Want to learn more about AeroBarrier to seal your current home or new build? Watch the video below to learn more!