Property Institute chief executive Ashley Church said the situation "threatens the fundamentals of what it means to be a Kiwi".
While numerous factors influenced ownership rates, Church singled out the Reserve Bank.
The Reserve Bank's policies had made it "almost impossible for first home buyers to get into their first home and risk locking in a fundamental social change that will affect Kiwis for a generation".
The bank in 2015 introduced loan-to-value ratios that required most home buyers in Auckland to have at least a 20 per cent deposit. These rules were extended to the whole country last September. Property investors need a 40 per cent deposit.
Church said today that the restrictions had "totally missed the mark" and treated "first home buyers as expendable fodder on the altar of a misguided economic and social experiment".
"It isn't just about the value of the house as an asset - it's also about what you can do with that house. Mums and Dads use the equity in their homes to buy businesses, fund further education, fund their retirement and help out their kids. Those options won't be available for Kiwis who aren't able to buy a home and it's a disaster waiting to happen - not just for the individuals affected - but for the economy as a whole".
"There's also the impact on communities, from a generation of renters, who won't have the same ownership stake in the places where they live. That's bad news for our Kiwi culture," he said.