Stuff reported on the research saying the type of additional dwellings would include converting basements and attics, placing extra dwellings on existing properties or a detached residence in a backyard or off a rear lane.
The idea has been scotched by house affordability researcher Hugh Pavletich who said it was ill-conceived and would make no difference to pricing.
“All it does is add to the degradable housing stock by squeezing more people into a dwelling, and when it comes to selling a property it could be advertised at a higher price as a five bedroom house rather than a three bedroom house,” Pavletich said.
But Saville-Smith promoted the research as a way of helping solve the housing crisis by turning existing stock into far more affordable, fit-for-purpose homes without sub-division of land titles.
New Zealand also had many examples historically of partitioned large homes. These dwellings would not impinge on greenfield sites or vacant land. There was also an opportunity to introduce other forms of accessory dwellings, such as converting garages or adding granny flats, she said.
There could also be social benefits of allowing older people to remain in communities with more people around them.
“Prefab and factory build technologies and innovations are perfect for this. But we need to have district plans that encourage accessory dwellings which meet people’s needs and are safe and comfortable.
“We took a very conservative approach to making these estimates. We restricted our definition of a partitionable dwelling to a dwelling that had a bedroom for every person living in the original house and two additional bedrooms,” she said.
The report details the need for both local and central government to develop policy changes that support partitioning and accessory dwellings.
“There is a mismatch between house size and household size. Houses have got bigger while households have got smaller, Saville-Smith said.
Some older people in particular, may be missing out on downsizing, she said. The solution could offer asset rich but income poor households who want to downsize the opportunity to partition or do new-build additions.
Could hidden homes solve the housing crisis? Kay Saville-Smith talks about the research on Radio NZ
The research can be found here.