What Is Thermal Bridging In Buildings?

You heard the term "thermal bridging," and you're wondering what it means for your home. What exactly is thermal bridging? Is it negatively impacting your energy bills? If so, can thermal bridging be fixed?

South Central Services has insulated hundreds of homes with spray foam insulation. Thermal bridging is one of many concepts that is new to homeowners. You are not alone in wondering what it is and whether you need to worry about it. Thermal bridging does affect most homes in America, so let's address these common questions about thermal bridging.

By the end of this article, you will know:

• What thermal bridging is
• How thermal bridging works
• How thermal bridging impacts energy efficiency
• The relationship between insulation and thermal bridging

How Does Thermal Bridging Work?

Thermal bridging is a term often brought up when discussing building efficiency. Specifically, thermal bridging is a common way energy is wasted and lost. We insulate our houses to stop heat from entering our homes in the summer and escaping in the winter. However, even the best insulation can still face energy losses from thermal bridging.

In many buildings, heat can bypass the insulation layer in a wall. Walls are generally comprised of more conductive materials like metal, concrete, and wood. These conductive building materials can create a "bridge" for heat to pass through. The season will determine whether the heat is invading or escaping.

See the diagram below for a visual of how heat may travel in the winter.

Thermal bridging is a crucial concept for people who work in building design, construction, and renovation. The only way to prevent or stop thermal bridging is at the design stage of a building.

Thermal bridging is possible as long as conductive building materials are in contact with one another.

Is Thermal Bridging Causing Energy Inefficiency In My House?

It is accurate to claim that thermal bridging contributes to energy inefficiency in your home. However, thermal bridging is only one of the many culprits of energy waste. In fact, if you looked at a pie chart of how energy is wasted in your home, thermal bridging would only take up a small slice.

A much bigger piece of the energy loss pie is insulation. Your home has a thermal envelope that spans the entire building. Your exterior walls, attic, basement, and crawl space all need to be insulated. Without sufficient insulation in these areas, you are essentially leaving your windows and doors open.

Windows and doors can also play a role in energy inefficiency. While you should address your insulation first, your windows and doors may also have areas of air leakage. Any gap that allows air to exchange must be sealed off with can foam or silicone caulking.

If your home needs energy-efficiency upgrades, you may benefit from a home energy audit. A professional walkthrough can help determine what is causing your high energy bills. Home energy audits prioritize home improvement projects to save you the most money.

Can Cavity Insulation Stop Thermal Bridging?

Cavity insulation cannot stop thermal bridging. While an airtight seal can prevent a majority of energy inefficiency, it cannot change the structure of a house. Thermal bridging can only be corrected through a change in the design of a house. Existing homes cannot fix thermal bridging without major remodeling work, and newly constructed homes can only avoid it through intentional design choices.

A common misconception is that adding more insulation or better insulation can stop thermal bridging. However, cavity insulation alone cannot address this issue. Thermal bridging is inherently linked to a home's design and construction. Once a building is constructed, the thermal bridges that are part of its design remain.

Exterior board insulation can stop thermal bridging. However, exterior insulation is usually only a solution for new construction homes or renovation projects.

Should I Be Worried About Thermal Bridging?

Think again about the pie chart of energy inefficiency. A large slice is taken up by insulation, with other pieces assigned to windows, doors, and HVAC equipment. Thermal bridging is a tiny sliver in the pie chart.

However, while the other pieces of the pie can be addressed through home improvement projects and upgrades, thermal bridging cannot be easily addressed.

If constructing a new building or doing major renovations, it may be worthwhile to address thermal bridging with exterior insulation.

However, if you’re just doing an insulation upgrade, it may be nearly impossible to address thermal bridging. Since it has little effect on your energy efficiency, thermal bridging is not worth worrying about. It is important to know the concept and understand the facts. However, thermal bridging is not a culprit to focus on when upgrading insulation.

The Bottom Line About Thermal Bridging In Your Home

If your home is newly constructed in a traditional way, you will experience thermal bridging issues. However, most homes in the United States have thermal bridging problems.

Until homes are built differently to prevent these issues, thermal bridging will remain a topic of conversation. Regardless, there are important steps you can take to control heating and cooling in your home. Insulation, airtight sealing, and HVAC equipment are all actionable items to lower your energy bills.

In new construction homes, every portion of the thermal envelope is open for insulating. For an existing home, the three most important areas to insulate are the attic, basement, and crawl space.

Would you benefit from a home energy audit? Find out if a home energy audit is right for your situation.

Interested in insulating your existing home to lower your energy bills? Check out these resources next.

• What Is Crawl Space Encapsulation?
• Does My Attic Need Insulation?
• Should I Insulate My Basement Ceiling?