Senior staff at the country's biggest home builder Metricon have been ordered to sit a three-day training course by the building watchdog.

NSW executives required to attend include Metricon's state director, chief legal officer, chief customer experience officer, general manager, building manager and operations manager.

The beginner-friendly course, which costs $2,250 per person, teaches students how to implement a quality management system to boost customer experiences.

It is one of five conditions the NSW Building Commission placed on Metricon Homes' licence in August in response to concerns over the company's handling of complaints, contracting practices and how it assesses quality standards.

It comes amid a 15-month investigation into the company, after the ABC in 2023 revealed the builder had been terminating dozens of fixed-price contracts and the regulator received a surge in complaints.

The 'root cause' of complaints

Finding out the "root cause" of recent complaints was another condition placed on Metricon's licence.

The builder has been required to pay an independent expert to analyse complaints lodged in the past six months and deliver findings so Metricon can "address any underlying system failure" in its complaints handling process.

The building giant also needs to pay an independent auditor to ensure it complies with its legislative obligations each year.

The conditions were published on NSW Fair Trading's licence check website on Tuesday afternoon, following questions from the ABC.

A spokesperson for Metricon said it had been aware of the requirements for months and staff had already completed the training.

Metricon CEO Brad Duggan denied it was embarrassing for Australia's largest home builder to have the stringent conditions imposed, and said he supported the Building Commission's decision.

"We have a very close relationship with the team there and we're doing everything we can to rebuild our reputation in the NSW environment," he told The Business on Wednesday night.

'We are open to review'

In mid-2023 Metricon briefly topped the regulator's builder list for complaints, prompting NSW Fair Trading to open an investigation.

Customers told the ABC that Metricon had arbitrarily terminated their contracts, blamed them, and offered inflated new quotes which they could not afford.

During this period volume home builders had begun collapsing, unable to profitably deliver on all the fixed price contracts they had signed up to.

Mr Duggan acknowledged Metricon and other volume builders had taken on "more work than what they could deliver safely for their customers" post-COVID.

But he fell short of apologising to affected customers.

He said Metricon had recently posted a $80 million turnaround and was back to delivering single storey homes within 100 days.

Probe into Metricon ongoing

A spokesperson for the Building Commission NSW said the probe into Metricon's "contracting practices" was ongoing.

Founded in 1976 and headquartered in Melbourne, Metricon has been the largest home builder in the country for the past nine years.

In the 2023/24 financial year, it commenced 3,894 home builds across Australia, down from 4,693 in 2022/23.

This week it announced Sumitomo Forestry Australia, a subsidiary of a large Japanese firm, would acquire a 51 per cent stake in the company, with a pathway to 100 per cent ownership in a number of years.