It has plunged many communities into the dark by turning off street lights at night to save money and energy, with some arguing it has been at the cost of safety.
But Norfolk County Council has now come under fire for keeping the lights on in its own building well after the majority of staff have gone home and are tucked up in bed.
Even though the authority has turned off more than 18,700 lights between midnight and 5am, photos of County Hall in Norwich - including this one taken at about 10.45pm on Tuesday, April 3 - show lights on across numerous floors.
A county council spokesman said the lights on the first to the eighth floors are operated by time motion sensors, which switch off automatically when people are not around and do not require people to flick a switch.
'We do however have some night teams operating on the site (including security) and when they move around the building the lights will turn on,' the spokesman added.
'In particular, we have a night cleaning team who will operate from 11pm to 4am – which would explain the pictures provided.'
It also said its lights were on the first to eighth floors are low energy LED lights but that its ground floor lights are on in the picture, as there is a security team in place overnight.
'We will however be looking to replace this system, with lower level lighting as part of a change to this area,' the council spokesman said.
Steve Morphew, leader of the Labour opposition group on Norfolk County Council, said: 'People would be surprised that lights at County Hall are on when street lights have been turned off elsewhere.
'There are questions that need to be answered. There might be good reasons but people are entitled to an explanation.'
In 2016, Norfolk County Council estimated it had saved £1.4m and roughly 7,500 tonnes of carbon dioxide emissions since 2008 by targeting its 52,000-plus street lights.
As well as turning off thousands at night, which itself had saved £693,232 by that point, it has also installed LED alternatives and turned some off completely.
It initially sparked concern among communities worried the early-hours black-out would lead to a rise in crime and anti-social behaviour.
However council reports have said there is no evidence to support the link.
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