Labour's plans for a capital gains tax would not encourage landlords to begin buying again, further limiting supply, he said.
Ring-fenced tax losses and significant new compliance costs had forced many property investors to increase rents and that was a further influencing factors, he said.
"As a result, we're in for big rent increases in some parts of the country over the next couple of years, with those increases already showing up in the Property Institute regional insights report," Church said.
Data from Barfoot & Thompson showed that from July to September last year, the average Auckland weekly rent rose 4.7 per cent to $542, from $520 during the same period in 2016. Barfoot manages more than 14,000 properties.
Church also predicted house prices would continue to flatten this year, mortgage rates would rise, new Auckland housing construction would only rise slowly and said loan-to-value rules would be further relaxed.