The built environment contributes significantly to rapidly growing world energy expenditure and tighter spatial interrelationships can exacerbate this effect in cities. The concept of the Inter-Building Effect (IBE) was introduced to understand the complex mutual impact within spatially proximal buildings. Our research sought to develop a systematic approach to disaggregate and quantify the influence of mutual shading and mutual reflection within a network of buildings. We built an urban building network model and conducted cross-regional simulations under different climatological contexts by examining mutual shading only and mutual reflection only, respectively. We then expanded our investigation by examining two realistic urban contexts in Perugia, Italy. We found the shading effect played a more significant role in terms of impact on energy consumption. The results of the simulations in varying climatological contexts also revealed consistent trends of greater impact on the IBE for shading and reflection in warmer climatic cities. These findings expand and deepen our understanding of inter-building effects and may help in the search to minimize mutual influences between buildings that lead to increases in energy consumption in urban environments. (C) 2015 Elsevier Ltd. All rights reserved.