Computer Simulation of Energy Use in Buildings: Predicted Versus Measured Results

The computer simulation of buildings is becoming more common, but the background knowledge required has always been considerable. With building simulation programs becoming more mainstream with built environment professionals, and UK building regulations now requiring simulation for some types of building, the uptake of simulation seems likely to increase. However, there is some controversy over the accuracy of simulation programs, regarding both the model creation and output. This paper looks at simulation from the point of view of an architect and examines three of the most likely programs an architect would use in adoption of simulation - EDSL TAS V. 9.4.1, IES VE 2018 and ArchiCAD 22 EcoDesigner STAR. These programs have been used to model a Dwelling in Scotland, which has previously had extensive physical building performance evaluation (BPE) conducted. The simulations results are compared with each other and with the BPE data. The programs were all found to have strengths and weaknesses. U-value calculators in all of them seemed inconsistent although all of the overall energy use estimates were more accurate than the standard assessment procedure (SAP) - the method used in the UK for compliance with building regulations. The findings show that all the programs have positive attributes for architects, but despite having the poorest energy use predictions ArchiCAD 22 EcoDesigner STAR was found likely to have the greatest positive impact for an architect due to the familiar environment and minimal additional inputs. IES VE 2018 was found also to be of use due to the flexibility, support and Sketchup plugin, which can afford a familiar environment in which to learn. EDSL TAS was found to be the least suitable for practicing architects