Passive House construction adheres to five building-science principals: continuous insulation throughout the entire envelope without
thermal bridging; an airtight building envelope preventing loss of conditioned air and infiltration of outside air; high-performance windows and doors that manage solar energy for maximized heating and minimized overheating during cooling seasons; energy recovery ventilation; and a minimal space conditioning system.
This is achieved in several ways, but primarily by designing a building envelope with high insulation with minimal
thermal bridging. By adding the crucial element of fresh outdoor air being circulated with extensive heat recovery means that energy consumption is kept at a minimum.
The built-in R-Value also has potential to reduce impacts of
thermal bridging.
[8] Schock Isokorb[R], (2014) "Design Guide-Solutions to Prevent
Thermal Bridging", Kitchener, Ontario
Developed in Europe in the 1950s, EIFSs are defined as non-load bearing cladding systems that provide exterior walls with versatile, insulated, and finished surfaces, while offering excellent thermal performance to eliminate
thermal bridging. In Europe, systems similar to EIFSs are known as external thermal insulation composite systems (ETICSs) or external wall insulation (EWI).
Providing consistent insulation throughout the building and incorporating thermal masks to maintain air temperature are the best methods to prevent
thermal bridging.
The 4/4/4 wall configuration offers an R-Value of 21.56; in contrast to conventional precast/prestressed wall panels, its absence of solid sections eliminates potential
thermal bridging and bowing.
The structural girts inside the assembly were offset to minimize
thermal bridging, and
thermal bridging was modeled using the same heat transfer software (Figure 4).
Even the windows contribute to sustainability and resilience--the durable vinyl frames contain plastic foam insulation and numerous air pockets that help prevent
thermal bridging (the transfer of heat through materials).
Building Envelope
Thermal Bridging Guide--Analysis, Applications and Insights.
The code requires that wood-framed walls in climate zones 6 to 8 have both insulation in the wall cavity and "continuous insulation," which is uninterrupted by the
thermal bridging of the studs.
Contemporary energy codes specify "continuous insulation" to address
thermal bridging, meaning only fasteners (nails and screws) can penetrate the continuous insulation (not structural elements, such as brick-ties and z-girts).
