Building the future: A realistic grasp of human nature would create savings in buildings’ energy consumption

It would be ideal if people understood how buildings’ systems worked and were motivated to use them as intended. However, this is not the reality: people have a poor grasp of how systems work and use them sub-optimally.


Many view radiator thermostats as valve-like devices, without understanding the related meters or adjustment functions. The use of thermostats is characterised by misconceptions, which can easily lead to unnecessary energy consumption. What is more, the symbols used on thermostats are misunderstood; office workers in particular are unclear about what thermostats affect. Of course, thermostats do not provide users with understandable feedback telling them that their requests have been received and are being handled by the system.

Human behaviour is unpredictable

People use systems very passively. Most office blinds are left down all or most of the time. Around a third are never touched. Lighting is often left on needlessly. According to a survey, some 60 percent of lights are left on in European offices during the summer. Lights are typically switched on upon entering a room, but are not switched off as the amount of natural light increases. In many cases, all lights are switched on despite the fact that less light would suffice.

Most computers are left on continuously. Studies of offices have shown that up to 60% of computers are left on overnight. A range of explanations are given for this: the slow startup of machines, the pointlessness of switching them off, the small amount of power consumption in question, simply forgetting and misunderstandings, and the idea that shutting a computer down shortens its useful life.

People go for the easiest and fastest option. They do not behave in a logical, proactive or long-term manner. A building’s user is unlikely to react to minor discomfort, but acts frantically when discomfort reaches a peak. In such cases, conditions must be restored to a pleasant state immediately. If the settings are changed, they tend to stay in that position until the next ‘crisis of discomfort’.

However, people’s behaviour should not be regarded as irrational. It is more a case of a desire to restore comfort as soon and easily as possible without further reflection.

It is clear that people’s behaviour has a major impact on the energy consumption of a building. Various information campaigns have been held with the aim of changing behaviour, with varying results.

Building should accommodate people, not the other way around

It would be ideal if people could be taught the principles of how a building works. But this idea doesn’t even get out of the starting blocks, since busy office workers are hardly likely to enthuse about such training. The technical systems of many buildings are highly complex: understanding how they work cannot be set as a requirement for using them. Of course, a car can be driven without knowing much about how it works, since its controls are well-designed and easy to understand. A buildings’ system should be just as intuitive, but we are a long way from this.

We could adopt a different approach, rather than trying to instruct people on how to use a building and motivating them to save energy. We could make buildings as ‘behaviour-proof’ as possible. In such a case, people’s behaviour would not have a major impact on consumption, and inappropriate use of a building would not increase energy use.

Criticising users is therefore the wrong approach. I would not engage in finger pointing. While it is certainly worth teaching and motivating users, it is also clear that such users have little enthusiasm for using precious time to learn how to use a building.

The solution lies elsewhere, particularly in designers understanding how a building’s users think and behave – and creating solutions on this basis. Designers are often too optimistic about the use of a building, even assuming that users are like ideally and optimally functioning machine parts. In fact, users need freedom more than demands, particularly when required to be efficient and creative in their work.

The following three principles could serve as a guideline for improving energy-efficiency on the terms of a building’s users:

  • We cannot assume that users have the necessary information for using a building as intended. Although some do have sufficient know-how and skills, we must not design solutions accordingly.
  • We cannot assume that users are motivated to save energy (particularly at work). While some are indeed highly motivated, we must not design solutions accordingly.
  • We cannot assume that users will actively engage in energy saving. Even if some do, we must not design solutions accordingly.

We must therefore understand that people do not behave optimally with respect to buildings. People are people and buildings should accommodate them, not the other way around.

From the perspective of energy efficiency, the solutions favoured must be based on a realistic notion of human nature.

This issue is considered in greater detail by the following scientific article:

Karjalainen, Sami. 2016. Should we design buildings that are less sensitive to occupant behaviour? A simulation study of the effects of behaviour and design on office energy consumption. Energy Efficiency 9 (6): 1257-1270.

Sami Karjalainen VTT

Sami Karjalainen
Senior Scientist

Bulk or personalised heating services?

Too many ‘service concepts’ are based on the same bulk offering, no matter the customer. But doesn’t genuine service ultimately mean giving the customer the service product that he or she, in particular, really needs right at that moment? One of the logical justifications for bulk services lies in their rational and, from the viewpoint of service production, cost-effective nature. Or that, since genuine individual needs simply cannot be identified during the provision of bulk services, they cannot be fulfilled anyway.

A concrete example of bulk services is the production of heat for the end users of various premises. Heating for buildings is traditionally produced by adjusting heating and cooling systems to provide an ‘appropriate’ level of heat; for example, a temperature of 21.5˚C. After this, the end-users of the premises are told that if the ‘suitable’ temperature level happens to be unsuitable, they can select a more suitable one using individual controls in each room. However, surveys of real estate managers reveal that complaints are made about excessively high temperatures in over 90 per cent of buildings, but that complaints about excessively low temperatures are made in the same percentage of cases, according to the same surveys. Why?

I would explain this by suggesting that there was no means of identifying individual heating needs and thereby using personalised services to guarantee satisfied customers. In studies conducted at VTT over the last two years, I have found individual physiques to be the key factor in explaining personal heating needs. Of course, there is no right or wrong physique – we are all certainly individual in this respect. For example, there is one difference between the sexes that is of statistical significance: on average, men have 5 to 15kg more muscle mass than women. In light of this, I have one, eternal question for people who live in heterosexual relationships: if their clothing and activity levels are similar, which one will feel the chill more easily in the same temperature – the man or the woman? Stated in dry, engineering terms, muscle typically produces 1 to 4W of heat per kg of muscle, when fat tissue, our ‘fuel tank’, produces only 0.004W per kg of fat.

How, then, might the personalised heating services of the future work in technical terms? Three steps are needed:

  1. The heated/cooled space and its users need to be monitored
  2. A temperature setting should be made based on the actual need derived from the monitoring data
  3. The right temperature can be created for the space in question, using building automation and an HVAC system

So what should the user of the room do to ensure that this personalised service concept works in practice? Nothing more than entering the room and enjoying the comfortable temperature.

Of course, I am aware that many questions on such a service remain open and unresolved. First, at least two critical, privacy protection issues come to mind: how can confidentiality be guaranteed with respect to data on the physique of the person concerned, and how can we ensure that information on their movements while on the premises is not misused? The second practical challenge is technical: how can existing buildings be equipped with sensors and adjusted on a case-by-case basis? And then there is the problem of open-plan offices and meeting rooms: based on whom should the temperature be set when there are as many preferences in the room as there are people? On the other hand, the basic setting could be chosen on some grounds or other: the lowest setting for the season when in energy-saving mode; or the average of the preferences of those present – or the setting preferred by the most experienced or oldest person present. In any case, it would be better than the current situation, where everyone adapts to whatever the bulk service offers at the time.

I have been championing the testing of a personalised room heating service of this kind in suitable premises in VTT. I think there is considerable potential in the idea. Above all, it could increase the satisfaction of office users with the quality of their indoor environment – which would do no harm in terms of comfort and thereby productivity. In addition, this service concept would take the use, or lack of use, of the facilities into account – energy efficiency would improve if there was no need to heat or cool empty facilities. At the same time, we could even promote the commercialisation of high-tech via VTT.

Pekka Tuomaala, Principal Scientist