The non-essential lights of important buildings in the metropolis were also switched off from 8.30 a.m.to 9.30 p.m.as a symbol for commitment to the planet.
The lights will be switched off between 8:30pm to 9:30pm to coincide with the efforts of World Wide Fund for Nature-Pakistan (WWF-Pakistan).
Most parts of Brunei went dark on Saturday evening as thousands of Bruneians with glow sticks and candles joined people from 178 countries and territories in the global Earth Hour campaign.
"I think one of the reasons Earth Hour has blown up like this is that it's a relatively simple task that everyone can participate in".
What is Earth Hour and when it was started?
WWF say Earth Hour has successively campaigned for more climate-friendly laws and policies, including banning plastic in the Galapagos Islands. Millions of people had plunged into darkness for an hour so that the event could become a huge success.
A ceremony is also scheduled to be held at the Parliament House at 8pm tonight in connection with Earth Hour.
While many homes and businesses in the city will simply flick the light switch and go dark for Earth Hour, others are taking different steps to promote energy efficiency on Saturday. It is aimed at creating awareness for energy conservation, climate change and global warming. The Empire State Building in New York, Cesar's Palace hotel in Las Vegas and the Golden Gate Bridge in San Francisco are all on the list of participants this year for the United States.
Interior and Local Government Secretary Ismael Sueno enjoined the local government units to prepare appropriate activities for Earth Hour that at the same time would provide permanent consciousness on the importance of dealing with climate change.
Despite the terror attack in Westminster on Wednesday, the Houses of Parliament and Big Ben are joining more than 270 landmarks across the United Kingdom in switching off the lights for conservation charity WWF's Earth Hour.