Milton Keynes Energy Park revisited: Changes in internal temperatures and energy usage

A follow-up study was undertaken of 15 'low-energy' dwellings in Milton Keynes, UK, that were originally monitored for temperature and energy consumption from 1989 to 1991. These measurements were repeated in 2005-2006, with the results compared with the baseline using standardised daily external conditions of 5 degrees C. The 2005-2006 study found mean temperatures of 19.8 degrees C (95% confidence interval: 19.7-20.5) for living rooms and 19.3 degrees C (CI: 19.6-20. 1) for main bedrooms. Weak evidence was found for a 10% increase in gas consumption over 15 years to 87 kWh/day (95%CI: 77-96) and overall electricity usage rose by 30% to 15 kWh/day (CI: 13.6-16.5). Dwellings were classified into three groups of low, middle, and high-energy users in 1990. In 2005-2006, this high group consumed more energy than the other two groups combined and accounted for most increases in energy use; their gas usage rose by 20% to 130 kWh/day (110-150), electricity by 75% to 28 kWh/day (CI: 25.331.2), and had 50% higher energy intensity at 172 Wh/m(2) (CI: 150-195). On average the high group comprised dwellings that were larger, had been extended, and whose occupants had higher incomes than the two other groups. The results suggest that research for the development of energy policy, including building regulations, should focus both on how energy is currently used and on households where the largest future increases are likely to occur. (C) 2007 Elsevier B.V. All rights reserved.