Confederation Building is in the midst of installing a new motion sensor lighting system that aims to save money and energy.

"All of Confederation Building is going to be with new lights and motion sensors installed, so what you see when you drive by, Confederation Building won't be like it is today," said Environment Minister Terry French on Wednesday.

Speaking on the CBC show Radio Noon, French talked about the work being done after an email was sent in from a listener asking why Confederation Building was lit up in the middle of the night, even though few people were working.

French said the old lighting system was controlled by different zones on large circuits. That means if one light was turned on in one part of the building, many more lights would also get flicked on, whether or not the person needed all of the lights.

French said the government decided on the motion sensor system after learning it was more economical than re-wiring the building to correct the zoning problem.

Policy advisor Jackie Janes is with the province's office of climate change and energy efficiency. She said the new lights and motion sensors will save the province about $100,000 a year.

Janes said the contract to install the new system cost $1.2 million.

She said the energy savings from the move will make a positive impact on the environment.

"If you leave lights burning, it means you're using energy, and if that energy is being generated from the combustion of fossil fuels, those fossil fuels are emitting greenhouse gases in to the atmosphere," said Janes.

"By turning off the lights, if you turn them off and I turn them off, and our friends and neighbour turn them off, it may mean that Holyrood will have to work less hard, so it will burn less heavy oil, and will emit less greenhouse gases into the atmosphere."

The installation of the new sensors is expected to be completed in August 2012.