The European Parliament will turn off heating in its buildings for three days per week and adjust its thermostats for other days in a drive to save energy.
The move comes as European Union countries including France and Germany have rolled out energy savings measures of their own as they try to avert power or gas shortages during winter.
The European Parliament will switch off heating or cooling of its buildings from Thursday evening until Monday morning, and during holiday periods, according to an internal email from Parliament's environmental management service seen by Reuters.
"Members and staff can always work in the buildings but the temperature in offices will be reduced on these days," it said.
The parliament does not typically meet on Fridays, when many lawmakers travel back to their constituencies. Until now the heating has been turned down, but not off, at the weekend.
The buildings in Brussels and Strasbourg will also be heated to no more than 19 Celsius (66 Fahrenheit) and cooled to no less than 25C (77F), and external illuminations will be limited, the email said.
The curbs on heating and cooling kick in immediately, and are expected to save more than 2 million euros ($1.98 million)per year, according to Parliament's estimates.
European energy prices have soared to record levels in recent months, driven by Russia slashing gas supplies to Europe following its invasion of Ukraine.
The European Parliament's 705 lawmakers split their time between buildings in Brussels, where committees meet, and Strasbourg, where full-parliament sessions are held 12 times per year.
Some lawmakers criticise the energy consumption caused by this commute, including German MPs Daniel Freund and Peter Liese, who have urged Strasbourg trips be temporarily suspended.
The Parliament has so far resisted such calls, with President Roberta Metsola citing EU rules that require both locations to be used except for in "exceptional and unforeseeable circumstances" - such as during the COVID-19 pandemic when meetings were held remotely. ($1 = 1.0112 euros) (Reporting by Kate Abnett; additional reporting by Philip Blenkinsop, Editing by William Maclean)