Expanding Inter-Building Effect modeling to examine primary energy for lighting

•We build upon the Inter-Building Effect approach through modeling lighting energy use.•We apply the new method to a case study network of Italian university buildings.•We calibrated and validated simulation models through experimental monitoring.•We find that neglecting lighting need produces modeling errors in every orientation.•We define this expanded Inter-Building Effect (IBE) method as IBEII. Building modeling and energy performance assessment models have become fundamental tools for both designers and researchers. Spanning the boundary of single building analysis, the purpose of this paper is to investigate how buildings energy performance is influenced by Inter-Building Effects (IBE). Previous research has examined IBE impact on cooling and heating energy performance predictions across buildings, however, the impact of IBE on lighting, which may be substantial, has not been examined. We investigated this impact through coupled numerical and experimental analysis. We built upon and further validated the Inter-Building Effect approach through modeling the contribution of lighting energy use on IBE and through the use of empirical data for model calibration. We demonstrated that the energy use performance prediction deviations resulting from lighting IBE are greater than those from heating or cooling in a case study building and we described this expanded IBE calculation and assessment as IBEII. To further confirm the reliability of the findings, we replicated the analysis for four different building orientations and observed non-negligible primary energy requirement modeling errors irrespective of orientation. This demonstrates the critical need to include lighting in IBE calculations to more accurately model primary energy requirement for buildings in urban contexts.