Owners of apartments in a Kingston stage two block at 22-24 Eyre Street will head back to the ACT Supreme Court early next year after a mediation session with the developer, Morris Construction Corporation, failed to reach a resolution.

As an ACT Legislative Assembly examines the territory's building regulation, owners corporation executive committee chairman John Grant has gone public, saying the developer had not acted in good faith in more than six years of talks.

Mr Grant and the 120 other unit owners are challenging the developer in the court alleging serious building code violations, including alleged defective construction work in a concrete slab in the basement of the apartment block.

But the corporation and a host of parties to the case, including the ACT government, have denied any liability for the allegedly defective work, or in the government's case, approving a certificate of occupancy and use when owners claim it did not meet the building code.

Mr Grant said the owners corporation first raised the issues with the developer in August 2012, and negotiated in good faith for some four years, but a lack of action by the developer led the owners to file a building complaint in August 2016.

Since then, after further failed negotiations and the government failing to issue a rectification order for the alleged defects, the owners say they were forced to take action in the ACT Supreme Court in an effort to fix the problems.

The owners have only decided to go public in the wake of comments by the developer that the corporation was working collaboratively with the unit owners to resolve the situation - a statement Mr Grant said could not be further from the truth.

He said those responsible for the construction appeared to be fighting tooth and nail to deny what the owners believed was a reasonable expectation - that the A-class, structurally sound building promised by the developers was provided.

"The executive committee’s experience has been that Morris Construction Corporation and, or its representatives have denied the defects, attempted to delay and obfuscate any actions," he said.

"The owners of the apartments are stressed and frustrated by the poor quality of the building and the significant defects that could potentially threaten health and safety."

However, a spokesman for Morris Construction Corporation said it had participated in the mediation process fully and while that had not yet resolved the matter, it had led to further investigations by both sides.

“Importantly the building is safe and I will continue to work with the owners corporation in an attempt to resolve the matter," he said.

But beyond the builders, the owners believe the territory government should not have issued a certificate of occupancy and use for the building, claiming that the certificate misled buyers about the structural safety and compliance of the apartments with the building code.

In the legal proceedings, the government has denied all allegations about the certificate made by the owners corporation, and all defendants in the case have strenuously rejected the allegations of defective work.

But Mr Grant said, as the nation had seen in the banking Royal Commission, it was not good enough for a government regulator to simply give a rubber stamp approval or authority, and he now believed the construction regulatory system was broken.

"The government regulator must be expected to take reasonable steps to ensure that the building is ready for occupancy ─ it has a clear duty of care in this respect," he said.

"From the construction problems that have occurred in the ACT for many years and continue to occur today, it is not unreasonable to conclude that the construction occupations registrar fails in its reasonable duty of care."

A spokeswoman for Access Canberra said as the matter was still before the Supreme Court, of which the territory was a party, it was not appropriate to comment.

She also said the government was "committed to supporting safe and quality building in the ACT and would take action where is it appropriate".

Despite hoping a resolution could be reached, Mr Grant said the owners corporation was now losing faith in the ACT government's regulation of the building industry, and whether those responsible for the allegedly poor construction were actually genuinely trying to rectify the defects.

"The underlying laws and regulations are generally adequate, regularly reviewed and updated; the problem is lack of regulatory oversight and enforcement," he said.

"The sources of the problem are the absence of even basic regulatory enforcement and the abject failure of the government regulator to reasonably perform its duty of care."