An additional 190 solar panels have been added to the Shire Administration Building's western-facing roof, in a move to increase sustainability.
Combined with the 118 solar panels installed in 2010/11, the additions are expected to cover approximately 30 per cent of the building's total energy bills.
The building will now have a total peak production of 93kWp, equivalent to 16 households running with a standard 6kWp system.
Shire of Mundaring Chief Executive Officer, Jonathan Throssell, said this was a step in the right direction towards the Emissions Reduction Target set by Council in 2018.
"We are committed to the preservation and enrichment of our environment," he said. "Solar power and renewable energy are a great switch."
The solar panels are just one of the focal points of sustainability in the Administration Building, with a review of insulation next on the agenda.
Mr Throssell said sustainability and environmental awareness had been the priority in all Shire buildings since 2010.
"Any new construction incorporates energy efficient measures from the design stages and all older buildings are being gradually updated on an ongoing basis," he said.
"The inclusions of energy efficient measures mean we can eliminate a lot of extra costs in the Shire."
The upgrade took a month to install, and is expected to pay for itself within five years.