Cold Bridging Solutions for High Performance Building Design

As energy codes tighten and better long-term performance is required from buildings, addressing cold bridging – also known as thermal bridging – has become essential.

Applications in which cold bridging can occur varies, but it is any point in a building envelope where heat escapes more easily because a highly conductive material, like steel or concrete, creates an unbroken path between the warm interior and the cold exterior.

Without proper insulation, these weak points can be the culprit for the overconsumption of energy, lowering interior temperatures and creating the damp, cold conditions that lead to condensation, mold and long-term material damage.

For architects and engineers working towards more energy-efficient buildings, in particular projects striving to achieve Passive House or LEED status, addressing cold bridging isn’t optional, it’s essential to meet peak building performance.

Where Cold Bridging Typically Occurs in Building Design

In short, cold bridging can form wherever a conductive material interrupts the building’s continuous insulation layer, but some of the most common applications are as follows:

Balconies
- Where a concrete or steel balcony extends outward from the heated interior slab.
Canopies
- Similar to a balcony, where any steel bracket punches through the envelope to support an exterior canopy.
Parapets and roof to wall junctions
- Often sitting on steel or concrete that ties directly into the roof structure, bypassing the insulation layer.
Wall to foundation junctions
- Where a foundation wall or slab edge meets the structural frame above and the conductive materials allow for energy transfer.
Cladding
- The clips and fixings that hold rainscreen or metal panel systems to the structure create small bridges for heat flow and therefore contribute to a significantly low R-value.

Design Strategies to Fix Cold Bridging

When designing projects there must be a strategy in place to identify and specify solutions that combat cold bridging. For example, completing a thermal model can help highlight the weak areas early on. This must then be followed up with prioritizing the severity of the cold bridges and choosing the right product for the project, to ensure it will be as effective as possible and not under/over performing.

Cold Bridge Insulation and Material Selection

Enhanced insulation alone isn’t enough to combat cold bridging and instead specialized materials should be installed at these junctions in order to limit heat loss. Thermal break materials are the most effective solution in this instance as they can be customized to your project. Supplied at any size or thickness with specific products for various compressive loads, they are blocks of highly insulating material that restricts the movement of energy.

Structural Isolation Solutions for Cold Bridges

Structural isolation is the practice of physically interrupting a conductive structural path with a material that carries load but resists heat transfer, also known as thermal break materials. Our extensive product range can be specified for a number of applications, including:

Armatherm Cast-In-Situ for balcony/canopy connections
Armatherm FRR for heavy structural steel and moment connections
Armatherm 500 for parapet, wall-to-foundation transitions
ArmaGirt Z-Girt for cladding

Frequently Asked Questions

How can cold bridging be fixed in existing buildings?

Although more difficult and costly, cold bridging can be addressed at certain applications when existing buildings undergo retrofitting. For instance, it isn’t possible to install them at wall to foundation connections without demolishing the building, but where projects consist of upgrading the insulation of the property by installing cladding, ArmaGirt Z-Girt can be used as well.

What insulation methods reduce cold bridging?

Cold bridging can be reduced by implementing solutions that work towards achieving continuous insulation. This can include installing thermal breaks, external wall insulation and other high performance solutions to help stop heat from escaping through the traverses.

Where should cold bridge isolation be applied?

Isolation should be applied at any point where a structural element crosses the building’s insulation line and connects conditioned to unconditioned space, or interior to exterior.