Occupancy analytics: A new basis for low-energy-low-carbon hospital design and operation in the UK

This paper introduces an innovative approach to low-energy-low-carbon design for a new hospital in the UK. This innovation is achieved through an analysis of hospital operational policies and the impact of them on this performance. The analysis leads to new information and data, and it will be explained how this has a significant impact on the engineering design for the hospital's environmental systems. The work is a significant point of departure from conventional design practice, which largely focuses on the asset specification of the facility as a means for the achievement of this performance. There is now clear evidence that demonstrates that UK hospitals are failing to achieve the performance required by the UK Government's Carbon Reduction Commitment and this calls in to question how improved performance can be achieved by improved asset specifications alone. The primary source of this evidence emanates from the National Health Service (NHS) Sustainability Development Unit (2009. Executive summary. In D. Pencheon (Ed.), Saving carbon, improving health (pp. 8-9). Cambridge: NHS Sustainable Development Unit), which reports that actual carbon emissions from hospital buildings are increasing not falling, and that the rate of increase is diametrically opposite to that which is required (subsequent reports confirm this trend). The innovation presented in this paper concerns the development of a new building science called as 'Occupancy Analytics', the objective of which is to address this situation by providing new knowledge about how hospitals are used and then to use this knowledge to transform the engineering design process (and in the future: hospital operational management). The background to Occupancy Analytics is based on the assertion that as it is people that consume energy and not hospital facilities, then we should seek to understand how they are used and in particular how the working practices and processes (operational policies) of use impact energy consumption and carbon emissions. The importance of understanding occupancy is of fundamental importance to building science and has long been recognised as such within the building engineering profession. For example, it is the one major factor that determines the sizing and control of the engineering systems. In this paper, the author sets out the arguments for developing a new understanding of occupancy rather then reliance on formulaic principles (which largely characterises conventional design engineering design practice) that lead to poorly informed engineering solutions, which then lead to poor energy and carbon performance in UK hospitals. Occupancy Analytics has been implemented on a major new acute hospital in the UK. The objective of the implementation has been to establish a new benchmark in hospital energy and carbon performance. It will demonstrate how the development of new knowledge concerning occupancy should lead to a radical improvement in hospital performance. The results of the work undertaken so far have been substantial in their impact. A major finding was that conventional design practice grossly over-estimates occupancy leading to the poor energy and carbon performance described earlier. However, using Occupancy Analytics the author forecasts a reduction in carbon emissions for the new hospital of 34% and a forecast energy performance of 28 GJ/100 m3 or 280 kWh/m2, which is comparable to the best performing hospitals in Scandinavia.