Auckland has the most villages with 94 such places, accounting for around 22 per cent of the national stock.
The big six owner/operators Ryman Healthcare, Metlifecare, Summerset Group, Bupa, Oceania Healthcare and Arvida Group dominate the sector, JLL said.
But more than 80 per cent of 75-years-plus New Zealanders don't live in such villages.
The study called that the penetration rate, saying only 14.3 per cent of Kiwis aged 75-plus live in villages.
"The key target population for retirement villages are those who are 75-plus," JLL notes.
Stats NZ says almost 332,000 New Zealanders are that age but by 2048, that will grow by 501,000 to reach 833,000 people.
"This change in the structure of the population will continue to drive increasing demand for retirement villages," it said.
Canterbury has the second-largest concentration of villages, with 73 or 17 per cent of the national total.
But places there are much smaller, with an average of only 64 units per village, so Canterbury only accounts for 13 per cent of stock.
Most regions had an increase in unit numbers in the last year.
"The Waikato region had the highest increase in unit numbers of approximately 500 units.
This is followed by Auckland and Canterbury regions with an increase in unit numbers of 300 and 280 respectively," JLL found.
The Bay of Plenty has New Zealand's highest penetration rate for retirement village living, followed by Auckland then Gisborne.
By 2033, JLL estimates around 81,000 people will live in these villages.
"Assuming the resident to unit ratio remains at 1.3 this would mean that there would be demand for an additional 26,000 units by 2033," JLL said.
The report also noted calls for major reform, including from Associate Housing Minister Poto Williams, who wants clearer contracts and improvements to the complaints procedure.
"There are some changes the industry could start to make themselves around strengthening the complaints processes and reviewing contracts to ensure residents are fairly treated," Williams said last month.
It was up to owner/operators of New Zealand's dozens of villages to act because the Government had "no immediate plans" to reform the law, she said.
The Retirement Village Residents Association says it is considering this and plans action.