The thermal performance of the building envelope is becoming increasingly important with the implementation of the BC Energy Step Code, absolute TEDI targets within Part 10 of the BCBC and VBBL and high-performance building standards like Passive House and , LEED all helping BC meet its goal towards buildings being net zero energy ready by 2032.
As absolute energy and TEDI targets become more stringent, the heat loss through the building envelope becomes increasingly important, and determination of the real or effective heat flow through the envelope necessary. Thermal performance of the building envelope has evolved from the prescriptive requirements of nominal R20 walls and R40 ceilings to the use of effective R-values and continuous insulation being specified in building and energy codes to account for thermal bridges that were ignored in the past. Two- and three-dimensional, finite-element, heat-flow calculation software is also readily available and used by practitioners to calculate effective R-values. Resources like the BC Building Envelope Thermal Bridging Guide are also available to provide effective thermal values of various construction assemblies and details.
Specifying the building envelope thermal performance of assemblies requires an understanding of how building thermal performance values were calculated and used by the architect, energy and envelope design professionals to meet the buildings TEDI or other energy target requirements. Knowing what specific material components and their configuration, layout or attachment is also necessary in order to determine if the assembly meets the projects thermal requirements. All the various architectural wall, roof, glazing and sometimes below grade assemblies need to be identified and thermal values specified so appropriate thermal performance values can be identified for each assembly to allow constructors the ability to provide components and assemblies to meet the buildings thermal performance requirements.
- This presentation will outline and provide guidance and insight on how to identify, specify and review the thermal performance of building assemblies and components to meet increasingly stringent energy requirements.
- Attendees will be able to locate resources such as the BC Building Envelope Thermal Bridging Guide
- Become aware of how the more stringent requirements related to building performance of wall assemblies rely on an understanding of thermal bridging.