Consumers in Victoria have launched an unprecedented action against the state’s building regulator, whom they accuse of failing to protect home owners from poor building work, media reports.

The Age has reported that 36 victims of a poorly constructed townhouse development in Melbourne’s outer eastern suburb of Diamond Creek are launching legal action over a saga involving dozens of townhouses in the Rangeview Estate, whereby residents have experienced problems such as mould, inadequate fire separation, defects in roofing and cladding and general poor workmanship.

According to the report, owners Erin and Dave Robertson purchased a property within the estate in 2010 but were informed by neighbours only a few days after that they had purchased a lemon.

The couple later discovered that the slab had been built at lower than ground level, leading to water running underneath the house and causing floor skirting to swell up, discolour and grow mould.

A building consultant who assessed the properties also discovered that it did not have adequate fire separation, meaning that it could prematurely collapse during a blaze.

The class action accuses the regulator of being aware about deficiencies which were capable of causing serious injury or death in the event of a fire but being too slow to act.

One owner, Steve Balfour, said he complained to the VBA about the fire threat in August 2013 and an inspection was later conducted but that the regulator took almost two years to act and did so only after he informed them of his intention to contact the local council.

This action is the latest development in what has been a tumultuous life for the regulator, which was bought in in 2013 to replace the former Building Commission.

In 2015, a report by the Victorian Auditor-General’s Office (VAGO) report which examined the performance of the VBA along with the Building Practitioner’s Board, Consumer Affairs Victoria and the Victorian Managed Insurance Authority found that deficiencies in the VBA’s oversight of building surveyors along with a lack of coordination of monitoring and compliance activity across agencies meant that there was little in the way of assurance that domestic building construction complies with minimum standards.

VAGO did note, however, that the VBA had begun to address some of the recommendations contained in an earlier VAGO report into the former Building Commission in 2011.

A spokesperson for the Victorian Building Authority said the regulator was unable to comment directly on the issues raised in the Rangeview case as the matter was now before the courts and will be determined by a court, but said that the regulator wss confident it had carried out its statutory responsibilities appropriately and properly.

As the regulator administering the Building Act and associated regulations in Victoria, the VBA has responsibility for the registration and where appropriate, the investigation and discipline of building practitioners, or prosecution of those who have breached the Act.

The municipal councils, building surveyors and the VBA all have duties to discharge within Victoria’s regulatory framework.

The VBA maintains that in this matter we have carried out our statutory responsibilities. This included investigating the conduct of the builder, which subsequently led to the cancellation of his registration in 2016. The VBA also issued a direction to the relevant building surveyor to carry out his functions in accordance with the Building Act and, when this failed, initiated multiple investigations into his conduct which have resulted in him being referred to the VBA’s Practitioner Disciplinary Unit.