Early And Detailed Design Stage Modelling using Passivhaus Design; What is the Difference in Predicted Building Performance?

Abstract

In an effort to minimise the energy consumption in buildings, designers currently use a variety of energy simulation programs. However, despite the fact that those programs can make a significant contribution to the design of low energy buildings during the early design stage, the lack of detailed design information at that phase results in uncertainty in the modelled performance of the building. The uncertainty in building performance prediction has been the subject of previous research, yet no research to date has investigated the impact of design detail on the certainty of the performance prediction, this being the subject investigated in this paper. The paper reviews the potential source of design uncertainty at the early design stage, and investigates the impact of such uncertainty on the modelled performance of a small community centre located in the UK, this building being constructed to the Passivhaus standard. Although it is common for early design stage performance modelling tools to be different to those used in detailed design, this study is based on the use of the EnergyPlus simulation platform for both the early and detailed design performance prediction; this removes any uncertainty due to changes in the modelling tool, and allows conclusions to be drawn directly about the impact of design detail on the performance prediction.