Energy-efficiency is at the forefront of modern office renovations, but this often comes at the cost of comfort. So doctoral candidate Minyoung Kwon has turned things around: start by looking at the wishes of the users before you design their workplace. This does not necessarily have to result in higher energy consumption.
Kwon found that, as things stand right now, users are not considered until the building work is completed. There is a lack of clear design guidelines for renovations, so it is not known whether the accommodation is more comfortable after the renovation. And once the work has been finished, it is of course more complicated to make any improvements.
For her research, she studied the renovation of five office and education buildings dating back to the 1960s and ’70s. In each case, the renovation resulted in the Energy Label A. “But by no means all users were satisfied with the comfort, although you should be able to expect more comfort after what is often a rigorous and expensive procedure.” This is remarkable, as comfort is in the interests of the building owner: if the users are happy, the building is worth more.
To find out what users experience as comfortable, she carried out further investigations into the five renovated buildings. She placed sensors, kept a record of temperatures, and conducted user surveys. The user surveys showed that the preferred indoor temperature in the summer was between 23.4 and 24°C, and in the winter slightly lower: 21 to 22°C. Air quality also scored highly, as did visual comfort: it is important to users that an office has sufficient daylight or artificial light. For this reason the size of the windows is important, depending on the building orientation.
Environmental control systems
Another important factor that affects wellbeing is the extent to which people can influence their indoor environment. Even if they can make only minor adjustments to temperature or the provision of natural light, they feel more comfortable than if they have no control whatsoever. So it makes very good sense to install individual environmental control systems, says Kwon. “It doesn't require any high-tech solutions and it is only marginally more expensive.”
Office layout also affects wellbeing, with open-plan offices proving particularly unpopular. Office workers feel more at ease in a combination of private offices in combination with communal areas. She also discovered that the ideal position for a desk is around two metres from the window. This gives office workers enough sunlight yet does not get too hot on sunny days.
Kwon developed a model to measure the influence of the design on user satisfaction and energy efficiency. Based on her practical study, she was able to use this to predict energy requirements and the anticipated experience of comfort in various office models. Interviews with architects and building managers then helped her to formulate design principles for office renovations. “Using these design principles, it is possible to arrive at a user-oriented renovation design with predictable satisfaction levels and energy consumption. It becomes much simpler to find a balance between the two, says Kwon.
In a follow-up study, she hopes to further investigate the impact of individual control on the indoor climate and energy consumption. The impact that this has on user satisfaction is far greater than anticipated. She also wants to study the influences of different façade constructions on building comfort.