Non-repeating thermal bridging
These are trickier because they’re unpredictable. They tend to occur around openings like window fixings, loft hatches, and doors. They have the potential to reduce the overall thermal performance of the building. In general, there are also a few things you can do if you’re designing to minimise non-repeating thermal bridging.
Combatting thermal bridging
The best way is a fabric-first approach – start from the design up, considering how efficient your build systems and materials are from the outset. The overall shape of the house can also impact on its rate of thermal bridging. For example, dormer windows, as quaint as they may be, introduce many junctions into a structure. The more junctions, the more opportunity there is for heat to escape. This is the reason that a Passivhaus is usually built in as simple a shape as possible. When it comes to reducing thermal bridging, simplicity of shape is key.