Summerset's model could be attractive to Victorians and Australians generally, he said.
"The continuum of care is independent living, rest home, hospital and dementia, all on the one site. They don't have a lot of that for various reasons," Cook said.
In May, Ryman said new villages in Hamilton here and Coburg in Melbourne had received planning consent. Consenting was well advanced for new sites at Burwood East in Melbourne and Geelong in Victoria, it said.
Ryman had secured its eighth site in Victoria at Aberfeldie and had also bought new sites at Havelock North and Karori in Wellington.
Summerset's June half-year accounts showed an $800,000 provision for tax but Cook said no tax was paid: "We spend $200m to $300m a year on properties and if we were not building that, we would pay tax. We pay no tax while we're building."
Summerset's half-year net profit after tax dropped 9 per cent from $90.3m in the half year to June 30, 2017 to $82m in the latest period but Cook attributed that to lower rises in property valuations.
Summerset is reconsidering its development plans at St Johns, Auckland after an over-height application was rejected but Cook refused to say what height might next be applied for.
The site was recognised as "perfect" for a retirement village, he said, "and we're pretty confident we will get a village there. We need to work through that."
Cook is concerned about staffing levels in the aged care sector, saying immigration changes to visas and long-term skill shortage categories by the previous Government had made life harder for his business which employs 1300 staff and has 900 hospital beds in its villages.
"It takes longer to get someone," he said, but that varied between regions.