Engineering design for in-use: Modelling of occupancy presence

This paper introduces an innovative approach to the analysis of In-use to inform the engineering design of an acute hospital in the UK. It is set in the context of consistently poor energy performance of UK hospitals where energy performance has largely remained stagnant since the 1990’s. Why is this, when regulation has sought to dramatically improve it? The research reported in this paper takes the form of a case study for the engineering design of the new hospital. The project sought to understand the In-use factors that impact the engineering design process in the forecasting of energy consumption. Through TM46, The Charted Institute of Building Services Engineers (CIBSE) has identified apparently significant inaccuracies in energy forecasts in health care facilities.

The authors’ hypothesis is that the issues that lead to poor energy forecasts may also be the same issues that ultimately lead to poor acute hospital performance. The authors’ research has identified that with a poor understanding of In-use, engineering designers are often obliged to make substantial assumptions concerning In-use, which can substantially impact the ultimate building energy performance. The research identified that occupancy presence and the associated diversity profiles are significant unknowns at the design stage, and it is here where assumptions are often made.

The case study explains how the author has developed two methods to enable the engineering design team to understand the impacts of In-use. The results of the two methods have generated new knowledge concerning the impact of In-use on the engineering design. Forecasts of In-use energy consumption also suggest a dramatic improvement.