Numerical optimisation through dynamic simulation of the position of trees around a stand-alone building to reduce cooling energy consumption

Numerical optimisation through dynamic simulation should consider the influence of urban microclimate on the energy balance of buildings, to reduce the energy consumption of the residential sector, even if a full interaction of the two different simulative resolutions is still under development. The current study employs free software readily available and widespread in professional practice to explore the currently available possibilities to analyse the dynamic interaction between microclimate and building. It combines dynamic simulation, parametric design and genetic algorithms to identify the optimal position of trees around a 1-floor and a 2-floors building, located in Rome, as a function of the maximum reduction in energy consumption for cooling during summer season (from 21st June to 22nd September), taking into account only the shading effect of trees. The results confirm the significant influence of vegetation's shading effect for energy savings: energy consumption in the 1-floor building decreases from 11.1% for the 1-tree configuration up to 44.4% for the 5-trees configuration; in the 2-floors building, the reduction goes from 12.8% up to 48.5%. For each configuration, the optimised positions generally favour the east and west sides. The optimised positions of the first two trees have a paramount effect on energy consumption reduction, above 20% in both models, while there is a sharp decrease in energy consumption reduction between 2-trees configurations and 3-trees configurations.