Brookfield Multiplex has completed the first stage of the non-process infrastructure at the Roy Hill iron ore mine.
The company was awarded the $70 million contract late last year, and began work in March.
Since that time it has built, and now handed over, the Go Line buildings and gatehouse for Roy Hill.
The Go Line is an administrative facility that workers attend for shift changes and to pick up and re-fuel their vehicles.
The steel frame structure of the boilermaker, as well as the heavy and light vehicle workshop buildings are also complete, with the handover slated for the coming weeks.
According to Brookfield WA regional managing director Chris Palandri as the facility and construction is on track for opening later this year.
"The gatehouse and Go-Line buildings are the main administrative terminals required to ensure the smooth operation of the mine site, so that's why they are the first to be completed as part of our staged works program," Palandri said.
"These facilities were delivered within just eight weeks, so we are pleased with the progress we have made on site - we are working to schedule and budget.
"We will now move on to delivering the next stage of the facility, which includes completing the boilermaker and vehicle workshops and remaining Heavy vehicle, light vehicle service building in September, which will then be followed by the administration buildings to be completed by December."
Brookfield also built Roy Hill's $200 million accommodation facility.