@marek Yeah, around 60% houses are energy efficiency class D and below.

But the advice is quite counterproductive. Periodically switching off heating in your house makes even less sense because all accumulated heat will be then dissipated into the air and when you switch heating on again, it has to catch up and will use even more energy.

Same for switching off heating in unused rooms - these will just cool down adjacent rooms which you *want* warm, so again more energy used for heating.