Energy Interventions in Non-Domestic Buildings: Energy Saving, Occupants’ Satisfaction, Well-Being and Productivity

The UK government adopted the Climate Change Act in November 1990 and is committed to 80% reduction of their emissions by 2050 on 1990 levels. The building sector has been identified as a key potential contributor to meeting this target. About 18% of carbon emissions in the UK (100 million tonnes of CO2 per year) are generated by non-domestic buildings. The majority of existing buildings today will be standing in 2050. Therefore, making existing non-domestic buildings more sustainable can play a vital role in meeting UK targets. Recently, building performance evaluation has attracted more attention in the UK; however, it has been found that CO2 emissions from buildings, particularly green buildings, are usually two to three times more than had been predicted. This is because some of the assumptions made by designers at the design stage are not informed by what actually happens when a building is in use; and occupants’ behaviour is not usually considered.Halcrow aim to investigate whether/how innovative interventions can be employed to save energy without compromising occupants’ satisfaction, well-being and productivity. Halcrow’s recently refurbished HQ, known as Elms House (EH), has been taken as a case study for this research. Employees were moved to EH from two other London offices, one of them being the old HQ, Vineyard House (VH), adjacent to EH. This research looks at two different interventions: the first (and main) intervention was to provide a newly refurbished work environment, while the second is to introduce interactive posters to the building which will encourage employees to save energy at their workplace. An employee benchmark survey and two post-occupancy surveys were conducted to indicate to what extent the first intervention has improved employees’ level of satisfaction with their environment. Also, a full year’s energy data were collected in order to assess whether the new building is likely to be more sustainable than VH. The results showed that, in terms of energy consumption per m², the first intervention was a success. However, the energy usage per person was higher at EH. In terms of performance gap, CO2 emission at EH in 2011 was 3 times higher than what anticipated. The new environment has increased the level of satisfaction of employees, but not significantly so.