The WA Government is trying to ensure contractors get paid when they work on big projects.

The Government says it will introduce project bank accounts for all contracts worth between $1.5 million and $100 million.

The government-controlled accounts are designed to safeguard funds so that subcontractors are paid in full and on time.

The move comes in response to pay disputes that have held up major projects like the new Perth Stadium, Perth Children's Hospital and Elizabeth Quay.

But all of those contracts exceeded $100 million, and so would not have been protected by the measure.

Finance Minister Bill Marmion said the reforms are targeting mid-sized government projects to test if they could work on larger deals.

“This is the first step. This will involve about $250 million of State Government contracts,” he said.

“If it works, there is the option of course for the Treasurer [Mike Nahan] to implement them. That will be a call for him.”

The changes also include an enhanced contractors' code of conduct, more powers over pay disputes for the Small Business Commissioner, and a new unit within the Department of Commerce specifically for building and compliance.

New project bank accounts will be set up in late September, but some of the other changes will require legislation.