Summerset has bought two sites in Christchurch and says it plans to invest about $200 million into building retirement villages on them.
The sites in Casebrook and Wigram will be the company's first villages in Christchurch.
Summerset plans to build more than 200 townhouses and villas for independent living as well as cared apartments for those with more advanced needs on the 9.7 hectare site in Casebrook.
The 5.4hectare Wigram village will have more than 200 retirement units.
Both villages will have a village centre with recreational facilities and a care centre providing rest home and hospital-level care.
Shares in Summerset rose 1.3% on Wednesday to $3.23. AAP reports the stock has gained 42% this year.