Abstract

Current energy building codes and standards commonly consider the impact of thermal bridging in assessing building envelope performance. This research examines four thermal bridging calculation methods and provides a comparative study of the challenges, limitations, and effectiveness of each method to evaluate heating and cooling energy demands.
Each calculation method is applied to 21 different residential buildings covering a variety of building archetypes in Montreal. The equivalent envelope thermal resistance values are reported, and the impact on annual heating and cooling demand is evaluated using building performance simulation.
The results show that the underestimation of annual heating demand could reach 37% when the impact of linear thermal bridges is ignored. The annual cooling demand is also shown to be overestimated by 14%. In addition, the variation in Window to Wall Ratio (WWR) and Vertical Surface Area per Floor Area Ratio (VFAR) are highly correlated to the heating and cooling energy demand deviation.