The environmental impact of the four-day work week: a sustainable solution?

The topic of the four-day work week is gaining popularity in many companies, both in France and abroad, at a time when the majority of French people are opposed to the idea of extending the retirement age.

Far from being exhaustive, and because our next NextGen Summit will focus on both the managerial and environmental dimensions of the regenerative enterprise, we propose to explore some of the impacts of this new form of work organization.

Experiments that are gaining ground

The topic of a four-day work week is gaining in popularity, despite the fact that the majority of French people oppose the idea of raising the retirement age. In 2022, Belgium introduced the possibility of working four days a week, without reducing weekly working times.
In France, the government has also launched a small-scale experiment by testing a 36-hour week over four days for Urssaf agents in Picardie.
This work model not only offers a better work-life balance, but also has positive impacts on the health and well-being of employees. Recent studies confirm these benefits.
One of the largest experiments on the four-day week took place in the UK in 2021, involving 2,900 employees in 61 companies. Participants’ working hours were reduced by 20 percent, with no reduction in pay. The results of this experiment are promising: 71% of employees reported a decrease in burnout, and 39% felt less stress.

But what about its environmental impact? This article explores the potential environmental benefits of the four-day work week, as well as the potential obstacles to maximizing these benefits.

Identifying the positive environmental impacts

As part of the “4 days week” campaign, Platform, a non profit group of organizations commissioned a report which reveals that a widespread reduction in working hours could lead to a 21.3% reduction in the UK’s carbon footprint. This is equivalent to 127 million tons of CO₂ per year. While this study applies to the UK, it calls for a more global reflection by public and private actors to use it as a driver in reducing their carbon footprint.

Reducing the carbon footprint of commuting

Reducing working hours, such as moving to a four-day work week, could significantly reduce CO2 emissions from commuting.
A study by the University of Reading indicates that a four-day work week nationwide in the United Kingdom would reduce the number of miles traveled by employees by 558 million each week.
This scenario would result in a 9% reduction in car mileage, which would reduce fuel consumption and CO2 emissions.

In France, commuting accounts for 4% of CO2 emissions. According to a study published in September 2020 by the French Environment and Energy Management Agency (ADEME), telecommuting offers an average environmental benefit of 271 kg of carbon equivalents per year for each day worked at home per week. Taking into account the travel induced by an extra day off, we can get an idea of the impact of a 4-day week.

A reduction in electricity consumption

Reducing work hours, such as switching to a four-day work week, leads to a significant decrease in energy consumption. An experiment in the U.S. showed that eliminating one day of work saved energy by reducing the use of energy-intensive office equipment, such as elevators, heating, air conditioning or office lighting.
A British study also found, by comparing electricity consumed at home vs. electricity consumed at the office, that a three-day weekend would reduce CO2 emissions by 117,000 tons per week.
While these studies do not directly assess the environmental impact of a four-day work week, they do provide some indication as to the potential environmental benefits of reduced working hours.

Potential Spillover Effects

Telework-related spillover effects are indirect or unintended consequences of the shift to home-based work that could reduce or cancel out the expected environmental benefits.

Some nuance on electricity consumption

According to the International Energy Agency (IEA), residential energy consumption increased in 2020 due to the COVID-19 pandemic and the shift to telecommuting.
This increase in home energy consumption is due to people spending more time at home, using more electronic devices (movies, social networks) and needing to regulate temperatures in their homes.
The energy efficiency of individuals therefore becomes a key factor in assessing the real impact of a four-day week on energy consumption.

Likewise, some businesses may choose to rearrange their employees’ work hours to maintain the same weekly work hours, but spread them over four days instead of five.
In this case, the environmental benefits may be limited.

Creating more mobility

With one less day of work, employees may choose to engage in more energy-intensive leisure activities, such as road trips or flights for weekend getaways. These activities could contribute to increased carbon emissions.

Increased consumption of goods and services

One less day of work could lead to an increase in demand for goods and services, such as eating in restaurants or buying consumer products. This increase in demand could generate more carbon emissions related to the production and transportation of these goods and services.

Raising awareness of responsible consumption to limit rebound effects

To minimize spillover effects, ADEME recommends implementing accompanying measures, such as:

  • Encouraging employees to adopt eco-responsible behavior at home, such as optimizing thermal insulation and controlling energy consumption.
  • Promoting public transportation and soft modes of travel, such as walking and biking to social events and occasional trips to the office.
  • Educate employers and employees on good telecommuting practices and responsible use of electronic equipment.