Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
The prototypes were recently updated to address Addendum av, which characterizes the new thermal bridging requirements. The addendum contains data sets representing cases where thermal bridging is mitigated and un-mitigated. Since the 2022 prototypes represent mitigated thermal bridging (in climate zones 4 - 8, where required), the 2019 prototypes were updated to represent un-mitigated thermal bridging. Overall average de-rated u-values were determined on a floor-by-floor basis for multi-story prototypes, so that's why there are three different u-values for the ground, middle, and top floor of the medium and large office prototype.
Details regarding the calculation of overall u-factors that incorporate the thermal bridging assumptions will be detailed in a forthcoming Final Determination report.
| | 2 | No.2 Revision |
The prototypes were recently updated to address Addendum av, which characterizes the new thermal bridging requirements. The addendum contains data sets representing cases where thermal bridging is mitigated and un-mitigated. Since the 2022 prototypes represent mitigated thermal bridging (in climate zones 4 - 8, where required), the 2019 prototypes were updated to represent un-mitigated thermal bridging. Overall average de-rated u-values were determined on a floor-by-floor basis for multi-story prototypes, so that's why there are three different u-values for the ground, middle, and top floor of the medium and large office prototype.
Details regarding the The calculation of overall u-factors u-values that incorporate the thermal bridging assumptions will be detailed in a forthcoming Final Determination report. report.
| | 3 | No.3 Revision |
The prototypes were recently updated to address Addendum av, which characterizes the new thermal bridging requirements. The addendum contains data sets representing cases where thermal bridging is mitigated and un-mitigated. Since the 2022 prototypes represent mitigated thermal bridging (in climate zones 4 - 8, where required), the 2019 prototypes were updated to represent un-mitigated thermal bridging. Overall average de-rated u-values were determined on a floor-by-floor basis for multi-story prototypes, so that's why there are three different u-values for the ground, middle, and top floor of the medium and large office prototype.
The calculation of overall u-values that incorporate the thermal bridging assumptions will be detailed in a forthcoming Final Determination report.
Edit: Here is the Final Determination report.
| | 4 | No.4 Revision |
The prototypes were recently updated to address Addendum av, which characterizes the new thermal bridging requirements. The addendum contains data sets representing cases where thermal bridging is mitigated and un-mitigated. Since the 2022 prototypes represent mitigated thermal bridging (in climate zones 4 - 8, where required), the 2019 prototypes were updated to represent un-mitigated thermal bridging. Overall average de-rated u-values were determined on a floor-by-floor basis for multi-story prototypes, so that's why there are three different u-values for the ground, middle, and top floor of the medium and large office prototype.
The calculation of overall u-values that incorporate the thermal bridging assumptions will be detailed in a forthcoming Final Determination report.
Edit: Here is the Final Determination report.
Edit2: This response details the calculations involved in derating the wall u-factor for the Small Office prototype in CZ5.
