The WA Government says it is close to finalising plans to move 800 public servants from the Perth CBD to Joondalup.

The Government wants to move public servants from various sites to a single building near Joondalup's train station.

Proposals for the building are still under consideration, but a successful proponent is expected to be announced this year.

Finance Minister Bill Marmion said it would be a beneficial move.

“The purpose of decentralising some of our public servants to Joondalup is to reduce congestion on the freeway, provide a bit of an economic stimulus to Joondalup and also make sure there are services provided in the area of Joondalup,” he told reporters.

“So it's a bit of a three-way win.”

It is part of the LNP’s commitment to de-centralising the public service made following the 2013 election campaign.

The Department of Parks and Wildlife is heading to Bunbury, while the Department of Housing could go to Fremantle.

Joondalup is the Government's third relocation target.

The authorities say they want 11,000 square metres of office space in the new building.

The building will be undertaken in a private-public partnership arrangement with the Government, with construction to begin in mid-2016.

It has not yet been officially confirmed which public servants or agencies will make the move.

“The most likely outcome is that it will be the environment and water agencies, or parts thereof,” Premier Colin Barnett said this week.