Building morphology, energy performance, and simulation modelling: review of tools under the EPBD framework

This paper examines the role of virtual modelling and energy simulations as tools to analyse buildings energy performance, with particular emphasis on the influence of morphological configuration. In the current context, characterized by increasing attention to energy efficiency and the implementation of stringent European regulations, such as the Energy Performance of Buildings Directive (EPBD) and the requirements for Nearly Zero-Energy Buildings (NZEB), architectural design plays a crucial role in determining overall building performance aimed at implementing building sustainability and environmental impact. The study focused on the implementation of simplified models of building types derived from the aggregation of basic modules. These consisted in square base modules, gradually aggregated to form more complex architectural configurations, aimed at isolating and assessing the impact of building form on energy behaviour. Through a comparative approach, a sequence of typological configurations is developed by progressively aggregating the module: isolated building, linear aggregation, L-shaped, C-shaped, and courtyard configurations. For each one, key parameters such as heat loss surfaces, surface-to-volume ratio, solar gains, shading, and ventilation conditions are analysed, highlighting how increased compactness generally reduces heat losses while simultaneously affecting solar exposure and microclimatic dynamics. The analysis is conducted in relation to climatic conditions (Köppen classification), to establish the relationship between environmental context and morphological strategies. More compact configurations tend to perform better in colder climates, while more open forms facilitate natural ventilation in warmer conditions. Also, a primary survey of key energy and microclimate simulation tools, including EnergyPlus with the OpenStudio interface, Termus, TermiPlan, ENVI-met etc., is conducted in order to individuate potentiality and limits. Their general functioning, required inputs, and typical outputs are outlined, emphasising their role in enabling the simulation of alternative scenarios and supporting informed design decisions. Main results show that, under consistent boundary conditions, building morphology has a substantial impact on overall energy performance. Virtual simulations therefore emerge as a fundamental tool for informed design, allowing designers to evaluate and optimise solutions from the earliest stages of the project. In conclusion, energy design should not be considered solely as a technological or systems-based issue, but also as a central morphological aspect, in which building form and aggregation strategies play a decisive role.