NSW's home building insurer has been knocked back in a bid to introduce fresh documents into a long-running coverage fight that has already been to the Supreme Court and back.
The Civil and Administrative Tribunal's Appeal Panel on September 11 refused an application by NSW Self Insurance Corporation (SiCorp) to adduce new evidence in a remitted appeal over whether a company, CN1 Pty Limited, was a "developer" and therefore excluded from cover under its home building compensation insurance policy.
The ruling is the latest chapter in a dispute between SiCorp, which administers home building compensation insurance in New South Wales, and CN1, which had claimed indemnity after its builder, Willoughby Homes Pty Ltd, became insolvent during construction of dual occupancy dwellings on a lot in Kellyville.
Under section 3A of the Home Building Act 1989 (NSW), an individual, partnership or corporation on whose behalf residential building work is done is a "developer" if the work is connected to a dwelling in a residential development where four or more dwellings are or will be owned by that person. Under the standard policy wording, a developer cannot claim indemnity. SiCorp rejected CN1's claim on that basis.
The dispute first went before the tribunal in 2024, where CN1 won. The tribunal found CN1 was not a developer, treating each dual occupancy dwelling as a separate instance of residential development.
SiCorp appealed, and in February 2025 the Appeal Panel reversed the decision, holding that CN1 was a developer. CN1 then took the matter to the Supreme Court, where Kirk J found the Appeal Panel had erred by assessing CN1's developer status as at a time before the residential building work was done - around February 17, 2021 - rather than as at the time the work was actually carried out. The Supreme Court set aside the Appeal Panel's orders and sent the matter back for redetermination on that narrower temporal question.
When the appeal came back before the panel, SiCorp sought to issue a summons to CN1 for documents that were not before the tribunal at first instance - tenders, building contracts, development applications and consents relating to other lots in the same deposited plan, covering the period from January 2016 to March 2021. SiCorp argued that the Supreme Court's judgment had brought into sharper focus the broader factual questions relevant to whether the site was a single residential development, and the panel needed a fuller evidentiary picture to answer them.
CN1 opposed the application.
The panel applied the test from earlier NCAT authority, which holds that new evidence on appeal requires a persuasive reason to depart from the general principle that fresh material is not ordinarily admitted. Relevant factors include whether the evidence was available at first instance, why it was not relied on, whether it would likely have changed the result, and any prejudice to the other party.
On the first factor, the answer was decisive. SiCorp conceded it could have pursued some of the evidence earlier. It had put material before the original tribunal about CN1's ownership of other lots in the deposited plan, and had argued that Lot 544 was just one lot in a larger residential development. But it had taken the strategic view that the issues could be resolved by reference to just two lots - Lots 544 and 547 - and chose not to gather supporting evidence about the rest.
The panel was not persuaded that the Supreme Court's judgment had changed the evidentiary landscape. While Kirk J had clarified the timing of the assessment and identified a range of potentially relevant factors, the panel noted that a broad range of factors had always been capable of bearing on the characterisation of a residential development. In the panel's view, SiCorp had always known the other lots mattered but had chosen not to lead evidence about them - and that evidence could have been obtained at the time through the very process SiCorp was now seeking leave to follow.
On the second factor - whether the evidence would likely have changed the outcome - the panel found it could not say. The contents of the documents SiCorp sought were unknown, and it was not even clear whether the documents existed or were held by CN1.
There would also be some prejudice to CN1 if the evidence were admitted. While CN1 would likely be able to respond, it would still incur time, effort and cost.
The panel also confirmed it would determine the remitted issue itself, rather than sending it back to the tribunal at first instance. Both parties agreed this was the preferable course, given the panel's familiarity with the evidence and the confined scope of the remaining question. The matter is listed for directions on September 22.
The substantive question remains open: was CN1 a developer at the time the residential building work was done, around February 17, 2021? The panel will now decide that on the evidence that was before the original tribunal - without the additional material SiCorp wanted.
For claims teams and coverage specialists handling home building compensation disputes, the case is a pointed reminder that strategic choices about evidence at first instance tend to stick - even when an appellate court reframes the question on the way back down.
