Behave Yourself: How E.ON and Savills’ Cardiff office harnessed behavioural science to cut office energy use by more than a quarter

Behave Yourself: How E.ON and Savills’ Cardiff office harnessed behavioural science to cut office energy use by more than a quarter
  • Behavioural science experiment used simple ‘nudges’ to prompt a ¼ fall in energy use
  • Over a year, savings in a small office represented enough energy to run 81 laptops for a year or boil a kettle nearly 54,000 times1

E.ON and the Cardiff office of global real estate advisers Savills have come together to run an innovative behavioural science experiment, to test how businesses can encourage their employees to do their bit and reduce their energy use. These small and unobtrusive changes had little or no impact on day-to-day business activities but saw energy use fall by an impressive 26%.

The four-week experiment run in the city centre office revolved around Savills employees, comparing the behaviour of two sides of the office: one with a series of behavioural science inspired ‘nudges’ to prompt responsible energy behaviours, with the other running as a control group without any interventions, to monitor energy use over the same period.

Nudges are small interventions designed to prompt people into a different pattern of behaviour, such as switching a light off that they may have left on. These make use of behaviour change techniques to guide employees into more sustainable choices – for example habit formation and creating social norms where individuals change their behaviour to fit in with the group.

Given that Savills office already has its own building management system in place with energy efficiency measures such as pre-set timers for lighting which could not be controlled by staff, the experiment offered an opportunity to explore other ways that a business can save energy and the important contribution individual employees can play.

Anna Kuzniar, Associate Director at Savills Energy, said: “The results at the end of the four weeks show we can all do more to save energy. We’ll use the results to support our own sustainability targets, and to inform our advice to clients. With energy prices at an all-time high we know that reducing consumption can make a real difference to a company’s bottom line, as well as to its carbon footprint.”

Phil Gilbert, Director of Customer Solutions at E.ON, added: “Large scale technologies and smart systems often get all the attention when it comes to businesses making the most of their energy needs, but, from an efficiency perspective, it’s often the case that the first step is making sure you’ve eliminated waste and you are operating efficiently. That’s why we’re really excited to have come together with a forward-thinking organisation like Savills on this experiment and show there are improvements that can still be made, even in a modern and well-managed office.

“These fantastic results prove that behavioural science is a powerful tool, with small changes able to make a big impact on office running costs. I look forward to helping more of our customers use these learnings to save energy and money.”

For businesses looking to replicate the effects of the experiment, there are a few simple changes that you can make to help see reductions in your energy cost.

  • Install prompts across the office, to remind employees to use less energy – for example above light switches and printers, to remind users to switch them off when not in use. These can range from fun engaging stickers, through to small and simple pieces of text, depending on what works best for your office environment.
  • Appoint energy ambassadors to keep colleagues motivated and on track. One task includes checking everyone has switched off their computer monitors at night, leaving red and green stickers to indicate who has and hasn’t remembered. This encourages people to compare themselves to other colleagues and uses social norms theory, which shows that sustainable behaviour can be encouraged in environments (for example work offices) where individuals don’t typically have these habits.
  • Give regular feedback on how staff are doing and giving them a comparison – for example to other parts of the business or similar businesses. This maintains momentum as well as encouraging a bit of healthy competition.
  • Encourage goal-setting by challenging colleagues with clear goals to commit to. This takes advantage of the fact that we seek to be consistent with our public and personal promises that we make.
  • Change your default settings, for example on office thermostats. We all know that heating in the office can be a contentious issue, however our human nature is to go with the flow and stick to pre-set options. Change the temperature to be within a seasonally appropriate range and provide a prompt above the thermostat to remind people to keep within this.

For more information about how E.ON can help your business manage its energy use, visit

The science behind the experiment

At the core of this experiment, E.ON and Savills were looking to test how a range of behavioural science theories can be used to change employees’ habits and help reduce energy use – from switching off computer monitors and printers at night, to turning off lights and leaving the office thermostats alone.

The set-up of this office proved ideal for the experiment. Each side of the office has its own energy meter, which made it easy to directly compare the impact that small and low-cost nudges can have on our energy use at work, as well as the financial savings to the business, compared to a control group with no nudges installed.

The nudges used varied from simple stickers above light switches prompting people to turn them off, text above heating controls guiding employees to keep it within an advised range to goal-setting ‘contacts’ and assigned energy ambassadors to keep people accountable. The nudges installed were all subtle and low cost to produce, costing less than £50. The experiment was designed and delivered by a team of behavioural science experts from H+K Strategies.

The results

As a result of these nudges, the experiment saw significant reductions in the energy use, with the amount used for sockets and lighting falling by 4%. Meanwhile, with the experiment taking place in the colder autumn months, energy use for heating in both halves of the office saw a rise. However, while the control nearly doubled its usage, the experiment group only rose by a quarter2.

This resulted in a total saving of 26% in energy use for the half of the office undertaking the experiment. When applied to the entire office, over the course of a year, this represents an energy saving big enough to run an office of 81 laptops for 8 hours a day for a year.

These figures are significant when compared to other similar experiments to reduce energy use, which typically achieve 3-5% decreases. For example, a programme undertaken in the United States using letters comparing consumers’ energy use to other households saw just a 2% reduction3 in energy. Moreover, when considering the fact that the Savills office used for the experiment already had a building management system, this experiment demonstrates the powerful role behavioural science has to play in energy saving.


Behave Yourself: How E.ON and Savills’ Cardiff office harnessed behavioural science to cut office energy use by more than a quarter