Do occupants change behaviour when their home is renovated?

In recent years, it has become apparent that households in energy inefficient buildings use less energy than the theoretical calculations predict, whereas households in the latest, most energy efficient buildings use more energy than provided in the theoretical calculations. Based on this, some have claimed that the energy efficiency of a building affects the occupants’ behaviour in relation to heating so the occupants become less energy saving when the energy efficiency increases.

It has been hypothesized that residents of energy efficient buildings have higher indoor temperatures and in general a more wasteful behaviour than occupants do in less efficient buildings. This project tested that hypothesis by investigation of an extensive renovation of four apartment blocks in Denmark.

The heat use was measured for eight years before the renovation and one year after the renovation. Before the renovation, indoor temperature, relative humidity and CO2 concentration was measured in the bedroom and living room at 5-minute intervals for 4 months in 17 apartments. After the renovation, indoor temperature and relative humidity was measured in the central corridor at 5-minute intervals in all apartments in one block (63 apartments).

No evidence in support of the hypothesis was found. In most of the apartments, the temperature measurements were similar before and after the renovation indicating that the occupants did not increase the heating set-point as a result of the renovation. The heat use was reduced by 64% after the renovation and the measured use after renovation was lower than the calculated estimate of energy use.