How environmental attitudes and occupant expectations influence thermal comfort and occupant satisfaction within green buildings is explained by Dr Max Deuble, green building, sustainability and energy efficiency expert.
It is well-documented that the construction of green buildings can bring about substantial savings in terms of energy consumption and greenhouse gas emissions. However, the difficulty in optimising energy efficiency within these buildings is more than just their operational performance or green attributes, but rather involves the attitudes and behaviour of the occupants.
Despite current knowledge of the benefits of green construction, little is known of the mindset of the buildings’ endusers. Indeed, there is a general consensus that green buildings can perform well. However, the success (or failure) and performance of green buildings are both ultimately determined by their occupants.
World-class research investigating the link between environmental attitudes, occupant satisfaction and indoor environmental quality within green buildings suggests that ‘green’ occupants are the missing link.
The ‘forgiveness factor’
While buildings are primarily designed and built for their intended occupants, in many cases this is done without explicit consideration of the end users’ needs or preferences. As a result, many occupants do not understand how to operate their building, which often leads to high levels of discontent.
In fact, post-occupancy studies from around the world provide empirical evidence to support this notion. Moreover, such studies suggest that green buildings, especially those featuring natural ventilation, tend to be warmer in summer and cooler in winter, with more noise and glare.
Yet, despite these less-than-ideal conditions, it is also suggested that green buildings have much higher levels of occupant satisfaction. This ‘forgiveness factor’ (1) is a measure of how far people can stretch their comfort zone by overlooking and accepting inadequacies of their building’s thermal, acoustic and visual environments.
Often attributed to the occupants in such buildings having some degree of personal environmental control, the higher forgiveness scores typically found in green buildings could also indicate that occupants may have an understanding of, and connection with, the outdoor climate by virtue of the building’s design. However, could occupants’ environmental attitudes boost these forgiveness levels in green buildings?
Two office buildings – a mixed-mode and a naturally ventilated (2) building – were used as case studies. Results obtained from post- occupancy evaluations, supplemented with an environmental attitudes questionnaire, along with thermal comfort studies conducted over a 12-month period, indicated that occupants with higher levels of environmental concern, i.e. attitudes, are more forgiving of their building’s less-than-ideal indoor environmental conditions.
Despite experiencing significantly warmer indoor temperatures, occupants in the naturally ventilated building were more tolerant of their building’s shortcomings, compared to occupants in the mixed-mode building (3). Furthermore, occupants’ comfort expectations and perception of control were found to have a significant effect on their thermal sensations, especially within the mixed-mode building4.
Altering occupant behaviour
There are many reasons why buildings don’t perform as well as expected; however, the hardest-to-manage reason for longer-term performance gaps is the way people behave in their buildings. Individual occupants and the choices they make – such as opening or closing windows, overriding automated systems or leaving appliances on – directly affect the building’s energy performance.
While it’s estimated that 20 to 50 percent of energy use in buildings can be attributable to occupant behaviour, building users are unaware of the energy they use and its overall impact on the building’s energy consumption. Hence, building designers need to incorporate features that allow the building to be operated properly.
The use of adequate feedback systems and effective communication can provide meaningful real-time consumption information, which helps the building managers and occupants understand how their choices affect energy use. As organisations begin closely tracking occupants’ habits and occupants start to be more aware of their own energy consumption, people can start to be held accountable for less sustainable behaviours. At its core, occupant engagement is about occupant empowerment.
As building owners begin to set energy performance goals through green building rating tools, such as NABERS, Energy Star and the newly launched Green Star Performance, tenant companies and their employees also need to be on board with building-wide goals.
There is an impetus for occupants to be involved with their building’s performance and operation through educational and empowerment strategies. If these buildings are contracted to sustain high levels of performance, occupants need to feel empowered and connected with their building.
Greater knowledge of the building’s design features and how they operate will achieve effective, long-term occupant engagement programs and strategies, thus creating a building-wide culture of sustainability and green occupants.
Realising green potential
It is apparent that occupant attitudes and expectations play an important role in the way green buildings are designed, built and received. These findings clearly demonstrate the need to change people’s attitudes, expectations and behaviours toward green buildings to better reflect the design intent of the building.
Furthermore, the use of occupant engagement strategies – such as providing feedback, transforming social norms, occupant education and empowerment – will enable building users to become green occupants. The development of green occupants, especially in green buildings, necessitates that building users are more in tune with their building’s performance and function.
This research acknowledges that the forgiveness of green buildings can be cultivated, and given the multitude of sustainable behaviour literature, there is great potential for occupants to be ‘re-educated’ about the role buildings play in addressing global climate change.
By understanding how their environmental attitudes match the building’s green design features, such occupants can achieve high levels of satisfaction and forgiveness for the building, but, in doing so, can realise the building’s true green potential.
1 A Leaman and B Bordass. (2007) ‘Are users more tolerant of ‘green’ buildings? ’, Building Research and Information, 35(6): 662-673.
2 The naturally-ventilated building has no centralised air-conditioning system, whereas the mixed-mode building reverts to centralised air- conditioning when indoor temperatures exceed the 25 degrees Celsius trigger temperature.
3 MP Deuble and RJ de Dear. (2012) ‘Green occupants for green buildings: The missing link? Building and Environment, 56(10): 21-27. 4 MP Deuble and RJ de Dear. (2012) ‘Mixed-mode buildings: A double standard in occupants’ comfort expectations’ Building and Environment, 54(8): 53-60.