The membership of a taskforce will always play a central role in determining the credibility of its recommendations. If a group is stacked with people of a particular bias, its findings will probably be of limited value. When, however, Diane Robertson of the Auckland City Mission and Major Campbell Roberts of the Salvation Army were appointed members of the Housing Shareholders Advisory Group, it could safely be assumed that the whole range of options for improving social housing would be canvassed.

Duly, the group has delivered a report rooted in practicality.

Its starting point is that while New Zealand enjoys a comparatively strong position on social housing in terms of international benchmarks, the strains of a growing shortage of affordable housing are becoming apparent.

The current state-housing model will not, the group says, meet future demand. It suggests Housing NZ should focus on the "high-needs" sector while moving to become an "orchestrator" of third-party participation over the next five years. The latter policy would diversify the funding of social housing by increasing community sector involvement, thereby taking the pressure off the Government.

The means by which the requirements of the most needy would be met has attracted most attention. Commendably, the advisory group looks critically at what has become the "house for life" expectation of many Housing NZ tenants. A state house has come to be regarded as a right, not a privilege. Some 22,000 tenants, or a third of the Housing NZ portfolio, have been in the same state house for at least a decade. In that time, many would have had children leave home or other changes in their circumstances. This means the Housing NZ stock is under-used. Many of these tenants could quite easily move to private housing, freeing up their houses for those in greater need. The advisory group notes the Government has asked Housing NZ to explore options to "facilitate and incentivise" just this.

That much is welcome, although it is fair to ask why incentives should be necessary. When tenants take a state house, they should be in no doubt this is a temporary arrangement, and they should move on once their need no longer exists.

The report moves into more problematic territory when it dwells on the involvement of third-party suppliers of social housing. It notes that Housing NZ's one-stop shop is unusual internationally. The Netherlands, for example, has succeeded in ending state involvement in housing. It and Britain have capitalised on the legacy of 19th century philanthropists' housing associations and developed them into modern housing suppliers.

The problem is that no such tradition exists here. The question, therefore, is how such community housing will be delivered. Will it be by allotting some of the existing state-house stock to community groups, which would allow them to acquire funding to develop more social housing?

Or would it be through the Government funding community housing corporations, rather than just Housing NZ? The latter option would introduce funding contestability. But there would be cause for concern if transferring funding or assets meant involving community groups that had far less management expertise than Housing NZ.

Before going down that path, the Government should explore all the options for getting the most out of its state-house stock. At the moment, ineffective targeting is making it difficult to achieve sizeable inroads into the queue at Housing NZ's door. Addressing that shortcoming should take precedence over the more vexing issue of a new social-housing model.